My suggestion, I think there should be leaderboards separated into divisions or level based. If leaderboards were split up into divisions the levels should be something like this.
This could cover all main levels of pve,pvp, and ctf in one broad category without making each level have its own leaderboard.
Or you could make every level a separate leaderboard, All you would need is to add a level change option on the leaderboard to make it so players can cycle through to the level they're trying to look at. I feel this would possibly make other levels/the game more active. Giving people a chance to acquire being on the leaderboards again. And give them a goal to play towards everyday. Again this is just a thought, But I think it would be an awesome addition to the game!