I've noticed lately that the highscores look pretty weird, some people have less experience than others and they are at a higher rank.
Also I would like to point out that the xp gained is not the same for everybody (depending on game mode you have chosen).
Therefor i think that you should add the game mode next to the players name, because for example:
A - legend
B - Easy
A and B are training together, they train for 5 hours, A ends up with lvl 99, B ends up with 26-26M XP.
So either make seperate highscores for each mode, or let legends only have highscores.