Sub-Shini Releases

Ok, quick question (been using this board so much lately it's not even funny, how was I staff before, not sure) anyways, since sub-shini technically have two different releases, human/FB and shini, do the releases have to correlate? As in does the shini release have to be the same type/element as the human/FB release or is it possible for the shini release to be completely different?