To be honest, I think being down one rotation guy help helps in some ways. Not saying that the Celtics are a better team without Marcus Smart, but without him everybody's minutes sort of fall into place. You get Kyrie in the high thirties. Tatum, Brown, Horford mid thirties. Hayward low thirties. Then Baynes, Morris, Rozier in the twenties.
I don't thin they've flipped a switch, because I don't believe thats a thing. I do believe however that this teams has had 1 too many guys all year, that being down one may help them, and that their style of play and overall versatility plus the ability to game plan and the coaching advantage they have is better suited to the playoffs.