For solo it seems that the game is now balanced for you to fight and XP chain enemies 0-1 levels above you, and it's best for you to set leve enemies to as close to that as possible when soloing. There actually seems to be a ton of random gaggles of same-level enemies added. If you check around rank 10 camps you will probably be able to find something. At 14-15 you can try the non-aggro enemies in Shpshaoe (however it's spelled).