I went back and looked at the stats from PHI 4 games with BKN. They have a pretty tight rotation:
P. Tucker - J. Harden - T. Harris - J. Embiid - T. Maxey
Melton also plays starter minutes with Reed, McDaniels, and Niang pitching in with limited minutes. I suspect in a more competitive series, we will see even less of the last 3.
I predict that Horford is going to continue to be an x-factor for the Celtics. He has the ability to draw Embiid out from the basket. If we have RWill in, Embiid can sag and clog the lane. This seems like it will be similar to how Horford was able to draw out Capela and force him to defend where he isn't comfortable.
Tucker was not great in the BKN series putting up only 20% from 3. If he is not able to hurt us with corner 3s, that is a big help. Harden was 42% from 3 but only 34% overall so I guess that means he wasn't finishing at the rim. Maxey, Harris, and Melton were all hot from 3 vs. BKN. Embiid draws a double and these guys hit their shots. We need to rotate well and make sure that it is Tucker getting the shots and not others.
Embiid is the key of course. If he is at or near full strength, we will need to double him and not foul him. Horford and Grant I feel are good match up, not so much because of how they defend, but because they can both hit 3s and that will force Embiid away from the basket. It will be interesting to see how RWill is used. he was a negative +/- vs. ATL. He may not work well against PHI either.