I rage-quit Bretonnia after like the second battle. I have no idea how to play them, their only good units are cavalry but if you build your army around those then you can't actually perform hammer and anvil tactics because your infantry is so pissy it will fold before you even get the cavalry in a flanking position.
How to play Bretonnia:
1. Build farms fucking everywhere with those windmills and shit for unlimited money
2. Conquer Marienberg and every port you can find for more unlimited money
3. Infantry? What is that?
4. Build only cavalry. Maybe flying if you're feeling fancy.
5. Charge!
6. If enemy not dead, repeat #5
7. If enemy brought anti-large, write stern letter about balancing to GW and CA.
8. Then send in the Hippogryphs.
9. Upgrade Leon to max level with his regeneration and shit, then send him to solo entire armies as the single most powerful melee lord in the game.
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In all seriousness, they're kinda tough to play. Their armies revolve around specific units that buff morale. Stuff like the Grail Reliquae and heroes to make sure your front line doesn't run the fuck away constantly.
Bretonnia is one of those armies where you actually want to get morale buffs as your lord's bonuses to make sure your army isn't worthless.
But if you don't like the faction, the best thing to do is just play a faction you actually like. I don't really like Bretonnia either.