Yes more girls will assuredly give you more low level encounters! Each one should be refreshing all the difficulty levels beneath it though... Is that not working? So you do the lowest, it leaves then the next higher level should bring back the lowest again!
So you should be able to climb the ladder carefully...
But otherwise RNG is gonna RNG. But there is the fact that all the upgrade cards the opponent logic gets are face and ace cards. Maybe I should have it sprinkle in more low level cards. I think I gave the opponent logic the meta strategy haha. Maybe the highest level should employ that but the lower ones perhaps should just stupidly add whatever cards they come across.