all input is good input!
i've just never rigged any of my conforming clothing like that. 

if i was doing some chest armour i would have all of the groups that the mesh overlapped onto (ie; chest, abdomen, lShldr, rShldr) and then for the bones i would have all of the group bones and then i always add 1 bone to the top and bottom...so if the shldr's were the last group i would probably have a neck and forearm bones in there and if the abdomen was the last group then i would have the waist bone.

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