Bard comes under the Laketown list so he cannot lead Dale warriors. I love the models and have bought 2 boxes of dale to ally in with my Erebor army. I tend to use the bowmen quite a bit to get cheap ranged weapons. The only downside is Girion can only be taken under the Garrison of Dale army list but not the Army of Thror list...which kinda makes him useless if you want to have him leading bowmen (like me).
The standard captains are very good, they share the same FV as the dwarf captain.
Probably a good way to use dale would be to take a front line of D7 erebor dwarves then have dale warriors with spear & bow behind them.
Just my thoughts
hopefully more helpful than the post above