Lenshu and Rkmma are one in the same, RK has a smaller ring and requires more control to stop yourself from being tossed out of the ring by your launches. RK Would be good for comebacks are higher gravity from short distances, Lenshu for long.

I'd choose RK, but good luck finding many people that play it to proficient. The mod sort of died out. The Ring keeps things stable whereas in Wushu (not talking about box variants) the opponent can just run if they so choose. Less viable.