The minute Fielder truly starts hitting AL pitching those intentional walks will drop for Cabrera.
Secondly, most teams will do that to other 1-2 punches (i.e Utley/Howard, Tulo/CarGo, Mauer/Morneau, etc.)
Yes, you want to avoid the 3-run HR if you walk Cabrera to get to Fielder but you gotta look at two things:
1. Fielder is a double play candidate.
2. You get Fielder out in any manner besides the double play, you go directly to Delmon. And most pitchers would say "I'd rather pitch to Fielder and Young than Cabrera and Fielder."
Until Fielder goes on a torrid pace, Cabrera will still be pitched around a bit.