[tei-council] witList/Group query

[Lou Burnard]

TRAC ticket 332 states  gnomically "change witList to witGroup, allow it 
to self-nest, and drop @included."

I'm just about to make the recommended changes but would like to check 
that Council's recommendation was made in full understanding of the 
implication that a given witness can only appear in one witGroup (or 
witList). Certainly makes things simpler and clearer, but does it 
correspond with reality? Do textual critix never talk about overlapping 
groups of witnesses, or witnesses which appear in more than one group?