Bench Depth???

I'm coaching a 12U select (travel) team with a good friend of mine and we have come to an impasse on the size of the roster. I am leaning towards 14 players with 2-3 of them being strictly pitchers. Our top 2 pitchers would play the field when not pitching, but I want 3 on the bench to go to. My buddy thinks we should go with only 10 players to help keep playing time fairer and not to water down the team.

We will be playing approximately 50 games over the summer and I think we need more of a bench. What do you guys feel is the right size roster for this sort of team and why? Thanks in advance for any input.