But I think it can work. as I thought.
you can just test it in geometry editor.
select Actor then open geometry editor tool
in option menu>editing>merge fitted figure.
But after merge one figure,
merged figures (fit to) actor, can not use individual preset.
when you hope to change merged part, you may need to apply texture individually.
(but surface group are kept as same as before,, about each merged figure)
and even though I change Actor shape, other merged figure can not follow the shape.
and smooth modifier may not work anymore..
(there is no target to collison,, and we can not apply geometry editor for each surfaces)
But all these are expected ^^;
it may be useful after you make one character, then export is as one rigged figure for collada or other filt type,,
or may try with Graft items.
(I think ,,it seems useful for blender collada export,, ^^;)