First I'll deal with skills, position by position, then acquisitions.
My approach is to specialize my line elves for specific duties. For example, I give at least 2 of them Block and Diving Tackle. This allows them to hold the flanks of your defense, in the wide zones, which is important since that's where most teams drive the ball to exploit the defensive weakness there. An excellent 3rd skill for these players is Dauntless, as it makes them even more effective at doing so. Pro is a great skill for this as well, depending on the type of teams in your league. If you have lots of high strength teams, or star players, I'd generally reccomend dauntless. If your league is more finesse-oriented, pro might be advisable. Of course, it's always possible to get one or more of each as well :)
Another example of line-elf specialization is to make a few "armor specialists". (Wood Elves would never call themselves "Dirty Players"!) Give them Dirty Player, then Block, then Dodge, then Pro. Two of these is a good number, though you'll usually only need one on the field at a time (the other is a good backup in case the first is injured or ejected).
More line elf specializations include Block and Dodge Line-elves to put on the line (unless you can put a bunch of trees up there, which is always nice with AV10 and ST7), and a few Block, Dauntless, Dodge guys to deal with those pesky Black Orcs or Chaos Warriors. If you REALLY like some hitting power (and it'll shock your opponents, too), try a dark elf tactic...get Block, Dauntless, and Frenzy!
Some people even consider making a catcher or two out of the group, but I personally don't ascribe to this theory, since all your players are AG4 anyway, and because that's what catchers are for.
Also, early on, remember that you have more linemen then you will when the team is fully developed. The exact number depends on what specific rules your league uses, but even if you are allowed no star players or allies on your roster, there will always be 2 extra line-elves. (2 Throwers, 2 Wardancers, 4 Catchers, only 8 positions left). Use one of these for a leader. That way, when your team develops and gets more rerolls, you can just fire him. Use the other one as a "screw-up guy". This could be a death, a serious injury (niggler or downgrade), or just a guy whose skills didn't develop right. (a movement upgrade + an Agility upgrade is pretty useless for a line-elf, for example.)
By far the most important thing to remember when assigning skills to line-elves is what to do with doubles. Give them Guard every time. If they already have guard, and they roll doubles again, either ignore it or give them stand firm or mighty blow, depending on the player's role.
The only time to make an exception to the "guard" rule is for line elves who already have several skills aimed at another specific purpose, and would be better suited to another skill. For example, remember your two guys on the flanks with Block, Dauntless, and Diving Tackle? They wouldn't really have much use for guard. They would need either Mighty Blow (to help with the damage on their D. Tackles) or Stand Firm (to thwart the evil plans of certain Troll Slayers and Witch Elves if the D.T. doesn't work.)
A totally different, but also viable, approach, is to make a whole bunch of line elves exactly or nearly the same way...I've seen this done most often with the Diving Tackle skill. Give a bunch of Line Elves Block, Diving Tackle, and Dauntless, Pro, or Tackle, depending on your league's makeup (or some of each).
This has some inherent advantages, as well. Having a bunch of people with DT makes the other team have to really think to get around your defense. Also, a few injuries are easily replaced by clone elves on the bench, wheras the loss of a specialized line elf is tougher to overcome.
The downsides to this plan, and therefore my reasoning for not doing it, is that you are limited in what your players can do. There are lots of times when you need a player with a certain ability to maximize the chance of success of certain situations, and that ability is minimized here.
The main reason is that, for me anyway, it's no fun. Half the fun of building a team is building skills on lots of players, trying different combinations, etc... This is lessened or negated by making a bunch of identical guys. Besides, it's a lot more fun to give your guys an individual personality, with skills that enhance that. I guess it's the Libertarian in me, I can't stand the thought of faceless masses of players who are all alike...give them the freedom to be themselves! (or thems-"elves")
I tend to specialize my throwers with their skill growth, as well. Since I only buy one at a time (see Acquisitions section below), one thrower is always going to be superior to the other (unless one dies, which is actually pretty rare).
This 1st thrower is my "offensive" thrower, and he gets Sure Hands, Accurate, Safe Throw, and Strong Arm. This allows him to throw the ball extremly well, and extremly far should the need arise. He's basically a pretty standard thrower.
The other, later thrower (I usually buy him when the 1st reaches 26 SPP's, at the earliest, so as not to stunt his growth), becomes the "defensive" thrower, and he gets Sure Hands, Dodge, Block, and Safe Throw. He Takes Dodge and Block because, on defense, the thrower is often getting himself into slightly more dangerous situations, and therefore he needs to be able to defend himself a bit. Also, it's nice because that way he's not a defensive liability.
These guys are the most versatile, skilled players on your squad, and you only get two of them, as well.
Wardancers, by default, and by virtue of the high MA, and leap skill, need to be your hitters, blitzers, and "ball extractors". As such, good skills for them include tackle, strip ball, dauntless, and if you're lucky enough to get doubles, Mighty Blow. Another good use for Wardancers is to give them tackle and shadow, and with their high MA, they can give most players fits!
Another great fact about Wardancers is that they can really use any upgrade they get, esp if they roll it early in their careers. A ST4 Wardancer is one of the most coveted tresures in the whole world of Nuffle, and an AG5 on isn't far behind, as it really helps those leap rolls. Even MA upgrades are useful, what better time to try that shadow/tackle suggestion mentioned above?
Wardancers are arguably the best players in the game (which may explain why they're the most expensive). Learn to use them effectively, and you're a long way towards winning already!!
Important!If you roll a Movement upgrade for you first skill on a catcher, you needn't read past this paragraph! Make him a one turn scorer. The only other team that can do this regularly (in fact a bit more regularly) is Skaven, so take advantage!! Give him Sprint, then Sure Feet, then Leap. Then just use him on offense only, and then only after the opponent's wizard has been used if you value his life, he will be Public Enemy #1. Consider yourself warned!!
For the rest of you mortals out there, here are some other ideas for catcher development:
In fact, I've gotten word that Luke Williams has killed Morg N Thorg with a Wood Elf catcher like this! Way to go man!
Seriously, even if you don't get 2 AG upgrades, a passblocking catcher is very nice. It allows you to interrupt many passes, one way or another, and if you can get under the path of the ball, you get 2 shots at 5+ to snag it. It'll pay off eventually! This is also a good player to mix with the type listed below: Use Passblock to attach yourself to the catcher, then follow the catcher around the field!
Another good way to use this strategy is to dictate a passing lane for the other teams thrower/reciever. Get 2 passblocking catchers, and set up each 4 spaces from the sideline. This will force the other team to either pass over you (risking interception), or pass down the very center of the field. Either way is good for you, as with catch your chances of getting the ball are decent, and if not, the other player has just walked right into the heart of your defence, where your Wardancers are. Gravy!!
This second section is going to be, thankfully, much shorter than the first. :^) It would be even shorter, but this section, more than any, depends on the particular variations of rules you use, and therefore, I have to deal with that extensively. Also, these guidelines once again assume you followed my starting team recommendations on page 1. If you didn't, adjust accordingly.
Then, as the situation arises, continue buying Deeproots until you've reached your maximum of 4. This allows you to have a dominant, tough to kill front line, and takes a lot of heat off of your wood elves. Many coaches will concentrate on felling your trees, surrounding them with many players and fouling the daylights out of them. By all means, pretend to be very afraid of this tactic, all the while laughing at him while you rack up the score! Deeproot makes a great diversion!
For tournament time, if you have the cash, replace one of your trees with a Jordell Freshbreeze. His AG5 and Leap make him a diversion of another type, the scoring type, and it opens up your offense a lot. The reason I don't do this regularly is that it also increases the chances of dead elves a bit. The other downside to having Jordell around is that he tends to steal SPP's from your other players. But hey, if it's a tourney, it's all out, baby!!
This time, after getting your base team built up as before (2 Wardancers, 2 Catchers, 1 Thrower, rest Line-Elves), then buy a Deeproot. Avoid Rookie Treemen at all costs...you simply don't have the roster space for a player that only shows up half the time!!
After you have your 2 Deeproots, buy A human Blitzer Ally to secure the line, and give him skills like Mighty Blow, Stand Firm, and Dodge (doubles required) or Guard. He's really the only ally (besides the trees) you'll ever need.
If not, just do whatever you can (loan, bribe, rob convenience stores, etc.) to get him. Then, if your fellow Wood Elf coaches are either completely inept, or completely unable to get money for some reason, save for Jordell. He'll most likely be gone by now, though.
Then, go back to normal team building as per whichever section is most appropriate.
Gosh, I really need to split this up into two pages...too bad I already did all the numbering and everything. GRRR!!!