Remember when we gave early minutes to Jaylen Brown in the game 2 against Chicago ? He did a LOT of defensive mistakes and I don't think he can start aganst the Wiz. He was good provinding some minutes while starters rest, it's good like that.
I think KO is very precious off the bench to give some scoring and he is our best chance to have a player with 15-20 poins off the bench.
Smart brings some super energy and usually I like him as a 6th man, where he can replace AB if he fouls quickly or to shut down whoever you need.
So in other words, I would say no one of these 3. Amir underperforms but you have no choice but to start him, then finish with super small line-up. That worked twice and I rather be competitive at the end of the game, even if it means being behind the whole game.
Don't change what's working.