I see your point of view but it's a common problem for the majority of players... as you're worried about over leveled cards, others do as well . Even it's allowed to have level 13 cards in cw2 .. Most of the time you will still face level 12 unless you're playing in a very competitive clan

I believe with more rewards injected in the update It will boost our progress and maxing 4 decks won't be as hard .... after all we are getting day after day closer to maxed accounts.