It sort of doesn't matter, since wingsuiters create their own separation - and their flights are long enough that they are going to open last anyway. But in general they get out last, just because that way even with a huge screwup in flight paths, they can't go back through jump run while people are in freefall there.
In my experience, one of the bigger factors in deciding exit order is who has seniority and who wants to sit next to the door on hot days.