Looks good but
- Some Units are reduced to 2 Units max: Black Grail, Archers, Artillery
Your rule allows 2 units of BGK, 2 elven archers, 2 mortors/lobbers, so no one would ever use cannon or other lesser arty/archers and all other units can be spammed (many of same unit).
However I have found,
- Only 2 of same character allowed, except Super Units, then only 1 of each - 1Mortor, 1 cannon/lobber, 1 BGK , 1 Elven Archer etc.. -"can now include Mages".
Prevents this and is a tried and tested method.