Skin Clusters and exporting

Something I'm working on, whats the optimal way to rig if the number of skin clusters is a consideration? Skin Clusters take up time on export and I imagine on import altho its hard to say for sure since Unreal Doesn't say as much as it imports as Maya does while exporting.
The skinCluster binds only a single geometry at a time. Thus, to bind multiple geometries, multiple skinCluster commands must be issued. - maya Docs
So other than normal clean rigging practices, keeping object count low will help. So I guess the question is, when and how much do you merge objects together? b/c one might separate objects for shading group reasons. (more on that later)