(I.e. the popular seniors are the first deciders of which grouping the new high school freshmen belong in)

I would argue that this is a non-representative example since in most situations there isn't nearly as clear a division between the deciders and the people being sorted.

I think this is more accurate for individuals trying to become members of a group than it is of groups trying to change their relative position.

This can also apply when members of one group (e.g., people who believe in philosophy X) what to increase how many of their members are also in another group with fuzzy membership (e.g., the inner clique in the philosophy department).