Ben,  my colleague Kevin pointed out that I was wrong :-)  I confused the storage group rules with initiator group rules.  What you propose is legal, however messy as you point out.   I would caution that application of flags and consistent lun could get confusing with the mix of IG and WWN.  sorry for the confusion!
Hi everyone,  Besides that it would look ugly, is there any reason I shouldn't add one IG as a child to another IG that already has WWN's in it? The parent IG would end up containing a mix of WWN's and child IG's. I would think this would work fine, but I worry it might have some kind of hidden consequences.  Thanks for your help!
VMAX2 IG containing a mix of WWN's and child IG's