In JP (so eventually it will happen here, right?) they have an auto average sort, it snakes your 20 most "powerful" units like this:

1 8 09 16 17
2 7 10 15 18
3 6 11 14 19
4 5 12 13 20

For now I auto-sort my first team by power for a stronger Helper squad, then refer to squad 1 as I manually sort squad 2, which I use for pretty much everything aside from raid bosses.

edit: Technically it would be best to account for damage type, but weaker units are still weaker, you know? And honestly, the best way to use type advantage would be to have the majority of each team be a single type and place them where you're sure they'll face that type of enemy. Spreading them out for general purpose average teams isn't a bad idea, but don't worry too much about that type of balance. I'd be more worried if one of my teams was at move speed 200 than missing a blue unit.