Sort of, but not the way you're thinking. It bleeds off the high ones, but then they go back up as the low one catches up. So each group ends up fully charged, not with a few artificially low to match a weak group.
But you still have a problem, as a weak group that goes low quicker than the others is still limiting your pack power to the capacity of the weakest group, and its going to need lots of balancing. so you still end up with a weaker battery, but not because of bleeding off high groups. That is, in my mind ,the main reason to run a BMS... I can manually monitor the top balancing, but I've killed several batteries by having a group go to super low voltage during hard running that didn't get noticed in time, and something automatically protecting against that would have saved some hassles.