I also find on smaller pull runs, there's a bit of a happy medium. If you have a pack of 3 and the first 2 are down, check your healer's mana when the last mob is about halfway dead. If they're good, head for the second group. That last mob usually won't survive the run to the next pack and you pick them up for the next bunch of 3 (or whatever the actual number is).
It doesn't put EVERYTHING beating on the tank at once for the healer to keep up with and it keeps the momentum going. I've utilized this on a few occasions and it's gone pretty smoothly.