I got the basics of reclassing working
I've been building towards the system that Modern FE games use where the head and body are separate and can be mixed and matched for different character+class combinations, and I'm also doing the thing where every character has an assigned color palette that can be assigned to any class outfit.
I have a script where I can just feed it the head mesh, body mesh, color palette, and height modifier for a character and it assigns all the bones to the skinned mesh and it just werks.