I doubt there’s an industry-wide standard. I’m sure it’s totally dependent on the situation. If the game runs better by characters sharing UV’s/textures then that’s the way to do it. If the game runs better by separating UVs textures, then that’s the way to do it.
My inclination would be to err on the side of consolidating UVs so multiple objects can share the same texture. The negative there could be that each of those objects suffer from limited detail/texture quality.
