Baby is the more consistent defender, especially in the team concept. However, there are times where certain matchups favor either one or the other for whatever reason.
This is why we need to trust this coaching staff on this issue. They have managed to find a few favorable matchups that I would have never seen myself. For instance, Big Baby guards Timmay really well and Leon did fair job with Dirk considering the night the big German was having. If you would have asked me about these matchups before I saw them with my own eyes, I'd have said we'd get torched by it.