caster cleaves have a higher chance to win (generally) when playing in a tournament. it's impossible or at least very hard to play in tournaments and not make any mistakes, therefore caster cleaves are more reliable in tournaments, and that only means one thing, that caster cleaves have a higher/steadier chance to win, because they are less susceptible to mistakes costing them a game.
that, however, DOES NOT mean they are easier to play. no certain comp is easier to play than any other comp, because it all comes down to the players behind the comp, and what I mean by this as a Mage:
I will play RMP and it's going to be just as 'hard' for me to perform as it would be playing a caster cleave, you still have to work as much in the game, still have to perform your best, however if you DON'T perform your best, you're less likely to loss, that does not mean it's easier to actually play the game because of the comp.
happy to clear that up for you