If the story is done, then I guess it doesn't matter. If the chunks are long, maybe spread it out to avoid reader fatigue. But if they're short and just happened to be breaking points, you may as well lump them.
When I'm writing as I go, a lot has to do with how I feel about the nature of the story. Easy plots without much fuss get posted as I finish them. If I worry about having to revise something based on later developments, I might delay. One story, my longest on here, I posted three chapters delayed. That is, I wrote chapter 4 then posted 1, wrote 5 and posted 2, etc. That gave me time. And yet, if it's complicated or I'm uncertain, I might wait for the end. And believe me, that can take a while. I've had one long one partially written for four years now and I've posted none of it because I can't trust what I've written will stay. I've already chopped whole chapters that weren't contributing or were going the wrong way. That and it's been a bastard to write in the first place.