Hmm, I don't think either one is the 'easier' game, it doesn't make any sense. It's a multiplayer game. Whether it's easy or hard to kill your opponent depends on how good your opponent is playing. If he sucks it'll be easy, if he's good it'll be harder. It's the same game for both people.

It's like saying basketball is an easy sport. If you're playing against a 12 year old, yeah probably. If you're playing against Dwight Howard, it will be a bit harder.