In this hypothetical scenario, the Celtics would have the ability to rest Zion because they could move every player up in position, and not struggle offensively.
Prichard
White
Murphy III
Tatum
Porzingis/Queta
The theory would also be that having the right mentors around Zion and playing far away from negative influences, would turn his career around. The biggest issue for me would be finding out the level of damage he has done to his body as a result of his physical negligence.
Having the tandem of Zion Williamson and Trey Murphy III to replace Brown would offer alternative options that the Celtics have been lacking last season, elite shooting (Murphy III) and rim presence (Williamson). I also like the idea of offensive hierarchy.