In my humble opinion, I think just a little bit of cockiness, especially when its used to promote and give confidence to the whole team is OK(maybe even good). It should signal confidence, and believe me, other teams can smell fear. Arrogance is destructive to the team and rarely is a players talent worth having that arrogance destroy the teams cohesiveness. One D1 pitcher told my son " When you step up to pitch or hit, Know you've got the biggest di_k in the ball park". I told my son to keep it to himself!