Along with the theory of left brain controlling right hand, this fits my experience. With my left vs right handed play. The article this quote came from also says this. Well it sure fits my experience.

Well in That case My conclusion is that playing with both hands can strengthen the left right hemisphere cooperation giving a 2 to 1 advantage when playing someone that only shoots with the favorite hand.
My final conclusion: Practice with both hands can help balance the creative and analytical. As long as it's done in private no one will make fun of the weaker hand. My experience with team play is that sometimes the weakest player can save the day. And oh boy isn't it fun when they finally hit a home run.
Juggling is a favorite way to promote team play with my hands.