He's in the middle of the a forest with possible hostiles around, and it takes that to get his attention?
@Saxit I believe he is answering the question of how many 'can fit', not how many could stay there at once. At which point, we are talking about cramming people in there standing room only like an elevator, and then 6/m^2 makes sense.
It does mean it will be really crowded when he tries to fit the ~15 girls in there.