If the celtics win itll be because of Jrue, White and Porzingis
And that would likely mean stepping up in the big spots that Brown and Tatum previously would have dribbled the ball into traffic or bricked a shot
I don't see Brown or Tatum suddenly changing their psyche that previously lead to failure. If they are put in positions to succeed and make the obvious play with White and Holiday specifically picking up the slack in less obvious situations that require information to be processed quickly and with prudence, the Celtics could win in 5 or 6. They have the talent to do so.
Its equally likely that the Mavs win in 5 or 6 due to the aforementioned not happening while Luka and Kyrie close out games with poise.
Ultimately, it's a toss-up. I might put a longshot futures bet on White for MVP