Slip-editing one clip's endpoint and another clip's startpoint simultaneously?

If I'm working in a MIDI project, and I've got, say, a piano solo on one track, which goes for a few bars until, say, a guitar on another track "takes over", sometimes I want to hear how it would sound if the change (from piano solo to guitar solo) were to happen a couple bars sooner or a couple bars later.  Well, as it is, I have to do two separate slip-edits: First, shorten clip #1, then lengthen clip #2, making sure I make it line up perfectly with where clip #1 now leaves off (or starts).
 
Question:  Is there a way to group the two clips such that moving one's startpoint will automatcally adjust the other clip's endpoint by the same amount, simultaneously?  In other words, like we can do with separate takes in Take Lanes, except with clips in separate tracks?
 
From the Documentation, sure, you can slip-edit two (or more) clips in different tracks, but it's limited to either lengthening all (from the same left or right end) or shortening all (likewise).  What I want is to shorten one while lengthening the other, by simply dragging their "meeting point". (btw, is there a term for this kind of editing?  Would it still just be considered "comp" editing, even if it's not done in Take Lanes?)
 
Thanks for any insights.
 
- Bob K

Speed comping?