The reality is that our best lineups have Baynes in them. I have to believe Stevens knows this, and as much as I hate his small lineups, understand that Baynes needs to be healthy and rested for the playoffs.
There is no reason to play in 30 mins a night.
I hope that's the reasoning. Baynes is one of our most important players, strange as that may seem. He's a crucial factor in our defense and rebounding. Monroe is the better player, but Baynes is more important to this team and should start.
And I agree with the majority that we should always play two bigs. Horford/Baynes has been a great combination (to my surprise, actually) and on paper Theis/Monroe could also work very well. I hope that Theis and Monroe will play significant time together to see if chemistry develops between them.
There always needs to be context to stats, but I looked a little at the stats of the different line-ups and (apart from the implied importance of Baynes) I found that Brown was almost always in the best line-ups whatever statistic I sorted, maybe we are underestimating him. Furthermore Irving doesn't really stand out and is not in the best combinations when it comes to passing. Also I was not surprised that Tatum seems to be very replaceable by whatever bench player.