I would guess look at XP ranking. Even though you are both level 105, he might be higher XP total. Can't be power or 3 and 4 would be switched. Can't be server #, or 4 and 5 would be switched.

Hmm, then the only other thing I can think of is database order, or some kind of server # processing order based on server merge list. for example, all players from servers B & C were merged to server A, so when re-indexing the point list all the players on server A are done, then B & C are processed in the order they are listed in some reference file. Ideally, the list should be first person to get to that point level has the highest rank. But if it is going to be sorted, I think this list should be sorted by descending points, and then by descending level #, and then by descending power.