yea , game use tris, but when making model , we count as poly. so can be confuseYep tris Generally if we're talking gamedev we're talking tris. I'm so used to saying polycount in triangles that I didn't specify sorry.
You're assuming that all body parts will use 4K textures but that's probably not the case, some will probably need 2K. And you don't have separate maps for roughness, specular and AO in gamedev. You pack all of those into one single texture, along with metallic if you have a metal map. You can get all four of those into a single texture.
i see, my material/unreal material is using many texture , to show the diff layer of the skin, as skin are very complex .
if that the case then i think there will not be much problem.