I really doubt Howard and Rondo would have any issues. Howard and Smith are great friends, Rondo and Smith are great friends. Sure, friends sometimes have friends that don't like each other, but I don't think this would be like that.
Howard has seen first hand how good Rondo can be in the playoffs. He also knows Rondo loves to pass the ball, especially to bigs.
Yeah, I'm not buying the chemistry issue concerns.