Originally Posted by A Time to Screw

Just level the waifus you like.

Thinking about being optimal would ruin the fun.

I did that in other games similar to FKG before... It's fun and all, until your units gets raped at every single node in an event map o.o

- - - Updated - - -

Alright. So keep and grind Camellia, along with my other relatively-rare girls.

Are there any high level girls with crap stats that would be better for me to avoid if possible?

Ty for all of you guys replies btw

You CAN'T avoid anybody if you gun for "rare" (read: premium) girls anyway. RNG giveth what RNG giveth.
That being said, it is the game that can be cleared with silvers and event golds, so don't worry about performance much and enjoy your time with your waifus.