Basically what the other two said. We don't know what role each pokemon would fill in a team if we didn't know EV's, moves and all that jive. It would be helpful if you put that.
However, right off the bat, if you're using Mewtwo X, this is going to be ubers, not the standard tier, OU. Second, unless you're making a sun team, ninetales shouldn't be considered for a standard OU team. Third, half the current team you have is weak to fairy. Just a few observations before we start on the actual team moveset, EV's, etc.