To be honest you have gotten real lucky with your 5* girl rolls, Having one of each type and an extra will serve you well later on, especially stage 12 maps that have a lot of enemies weak to slice damage. One of the best ways to see which girls are worth focusing on is to open the premium gatcha contents tab and compare their max lvl stats. That was how I decided which 3*s to focus my lvls and affection on.

5* and 4* should always be focused before 3* until you have enough that you can't use them all. The stats / special moves and special abilities make them much more important.