Yeah, with one slot strategy, impossible in origimal game is so easy.
It even make me want quit want get hand on black knight. Too simple and repeatly combat. I think your opinion it really good. But I think if you can make sysem like exp: The more hero use one type creatures, the more this type creature decrease stats (like decrease 10% att, def, HP for Black Dragon after hero use this at 100 combat)
. It will require player can think more strategy.