Split single full-body fbx file into multiple body part fbx files?

Right now I have fbx files of full human bodies split into body parts. When imported into Unity, each body part is viewable from the Project tab.

This is proving cumbersome and I'd like to split each full-body fbx file into multiple fbx files, each one a separate body part mesh with its own Material and Texture. This way I can mix and match different body parts to create different humanoids.

What are the downsides of this performance and development-wise?