As simple as can be, make their effects of card draw increase by 1, aka if its combo on 2, make it 3, if its combo of 3, make it 4.
Then as long as you have Dukes of Crows Favor, all your CROW cards combo of 3 and above require 1 LESS combo to proc.
That way you make the game more fun and a reason to fight over the Duke of Crow favor + you finally add a counter to it and not make it 100% luck based.
Currently its just a billion cards with exactly the same effect, who ever get them first win, nothing to counter it.
Boring.