Changing default Row to certain characters

I'm at the point where I'm mostly done with FF3usME after all these years working on my hack so I recently just started tackling with hex editing. Reading these disassembly docs sure helps a lot and I made great progression in a week. However, I think I'm stuck atm, I want to change default Row for certain characters but I can't find anything in the docs.

Front row seems to be the default row for all characters. Is there a way to change the default row to Back Row to certain characters when they join the group for the first time? The ones in questions are: Terra, Banon, Mog, Relm and Strago.

For some reasons, Leo defaults in the Back Row when you control him during the Kefka attack in Thamasa and ironically, I would like to change his default Row to Front.

I couldn't find anything related to front/back row in any of the disassembly documents. I've been reading C2, C3 and EventScript docs a lot recently and I feel pretty tired as a result so I might have missed something.