This is what I kinda have to deal with...and it's not real fun
It wouldn't drastically affect your setup, because if the other side of stacking comes in, where it can stack in the direction you want..then it doesn't do it as bad.
And...about the only affect it'll have is the little loop it'd have to do to find out where stuff goes...pretty well a little array...
Constant changing around...meh, who wants to talk to a busy/away/offline contact anyways.