Aha ok. That already sounded very fast.
As boring as rerolling is, it's probably worth it to keep rerolling maps until you get one where everyone is inside. Shouldn't be too hard, and will make a big difference in run times. Obviously having them all inside AND all clumped together is even better, but I don't know the odds for that. Most info on the subject is for teleporting characters, in which case you want them all outside, where space is much tighter to begin with.