From what I've seen, the problem is closer to having enemies respawning too fast for comfort. And even then there's instanced missions mixed in, at least on the path I took.
But the sections that do require "kill x" missions... I'm just not expecting that many people to be in any given one at a time.
But the sections that do require "kill x" missions... I'm just not expecting that many people to be in any given one at a time.