In the current state you should consider it more like metaheads than metahumans. You just have to skining your clothes to the skeleton.
A standardization of the heads is fine because it is the most work-intensive part, and artists can focus on clothing.
The problem I see with collars is that if you want to sell it on the marketplace, you should sell it with morphing for all body types.
and without any type of tool that baked the morphing you want to use the characters will be in gameplay with an amount of morphs that are not necessary