Yeah, the usage of the word "cleave" in arena comp names has nothing to do with its actual meaning in English and very little to do with its conventional use in the rest of WoW (a "cleave" attack being one that does significant "splash" damage to a limited number of opponents near the primary target).
It's sort of like how the Japanese use English words as linguistic decoration with little respect for their actual meaning. Banana cleave! Brimstone cleave! Fake hair cleave! Clamato cleave!