I'm playing my 16th game with Slann right now, so I might have some first hand experience to add here.
First of all, Slann live and die with their Rerolls. You have
absolutely no Reroll saving skills: No Sure Hands, no Catch, no Pass, no Block, no Dodge. Especially the lack of Block hurts, you can't even do a single blitz/block without the 1/9 turnover chance.
Leap is a negatrait. Repeat this sentence 17 times, until you get the meaning. Leap is a negatrait. Don't even think about using the Leap skill excessively. Leaping around is an absolute no-go area. Never do it with your lineman. Only do it with your Blitzers if you can manage at least a 1 die blitz against the ballcarrier. Do it with your Catchers only if you would have to Dodge anyway. Leap burns Rerolls like hell, add this to the lack of Reroll saving skills, and you'll get the picture.
Since you need those Rerolls badly, you have to start with 3 at least. But since you need your positionals too, you can't afford more than 3 Rerolls. So start with 3.
My starting roster has been the following:
3x Blitzer: 330k
2x Catcher: 160k
6x Lineman: 360k
3x Reroll: 150k
Take a look at my roster, and you'll learn something about my tactics:
French Fugitives
As you can see, I've taken Wrestle on 2 Blitzers. It's a great skill for them, because they start out with Jump up. Add in Strip Ball, and they can even do a blitz with 2 dice against them, if there is no Sure Hands involved.
Those other two have Block, and will choose Guard next.
Catchers will go for Dodge, Block and Catch, so there's no room for much variation until they've reached their 4th skill up. I've decided to go the the +1 MA, because Slann are too slow sometimes. They have 8x MA7 in their team, which is great on average. But without any MA8 peaks, the team still feels slower than it is.
One lineman with Sure Hands is a must have. Luckily, I've managed to roll +1AG on another lino, so I have always 2 players to pick up the ball.
Offensive tactic is simple: Create the hole, storm in and form the Slann cage (4 Blitzers, 1 Catcher in the middle). Unless your opponent has Leap himself, he won't be able to blitz your Catcher. With MA7 and 2+ Leap rolls, you should be able to make the touchdown next turn.
Defensive tactic is more challenging: Try to spread your opponent across the field, don't hesitate to use your linos as cannon fodder. With AV8, they'll manage to slow down your opponent without beeing CAS'ed too easily. You should try to break your opponents cage. If your opponent is more of the agile/running type, just use Diving Tackle to break the cage. If he's more of the slow/bashing type, jump directly into the cage and try to steal the ball.
Some coaches prefer the Pro skill for Slann very much, to Leap more effectively. In my opinion, that's a bad choice. Remember: Leap is a negatrait.
My teams performance improved dramatically with the 4th Reroll, add in some of those Reroll saving skills, and I can the game I would like to on most occasions. The Slann power curve is similiar to Chaos: You will most likely loose your first games, but if you manage to get a skill on every player, they start to rock.
Edit: I don't share tenwitts opinion against Wrestle for those Blitzers. The only time my Blitzers are on the ground (due to Wrestle) is when they've wrested down the ballcarrier, or in my opponents turn, when they wrestle someone down defensively. In both cases, the situation is rather negative for my opponent. He just lost the ball, or has a big hole in his defense, while my player will stand up and move 7 square. Not the best time for a foul.
