I think the unit spacing will cause the animations to look funny on desyncronise animations option setting a bit like if you've ever got units stuck in one place and they stand on the same bit of ground but you can try it and simply run the mod with syncronised animations and it might work.

With the invisible units it would look odd because you would have units fighting who were invisible. You could set their defense to 0 and then they would all get killed really early in battle.

Myrddraal's solution is proberably best but mounts only have one attack value unless you can get the invisible mouts to fire projectiles. That is if you want a second ranged attack.