User blog comment:Jopjopjop/Volume 19 Spoilers/@comment-16281343-20141203074638/@comment-1359322-20141203084531

Probably because Ishibumi wants to focus a bit more on abilities/technique. He did keep on insisting that power < technique after all. So he decided that power + technique + support + wizard would be ideal, but having it on one person would be boring, so switch to team.

But seriously, i'm guessing Ishibumi is trying to hold back a bit on the power-up. Randomly increasing it without control is bad for the story after all.