It might be worth noting that we have settled in as a completely average (and falling) rebounding team this year. Partly by system/design as usual, but the early season rebounding surge has been fully reversed.
It's a valid concern, but I don't think rebounding is an issue you can afford to fix by compromising other areas, such as offensive competence.
Ed Davis just would not fit at all in this offense. Brad's system requires bigs that can operate a dribble handoff, pass, cut, and make wide open mid range shots. I don't see how Ed Davis fits into that at all. It's not just the lack of shooting.
It matters for some matchups. As the originator of this thread, I completely agree that there are some teams against which Davis would be pretty useless, such as Golden State and Houston. But against a team like Detroit, it would be very useful to have two players who can fill the center role against Drummond, leaving Al at the 4 for the majority of the game. The same is true with Miami and New York, all of which are teams we could see in the first two rounds.
One of the main things that make Stevens a terrific coach is that he’s very good at figuring out how to put players in roles that maximize their strengths and minimize their weaknesses. Davis isn’t a good passer? Then you don’t put him in situations where he’s supposed to pass. He’s a great rebounder? Then you don’t have him switch on defense. He gets 50% more screen assists per minute than Baynes, and double that of Horford? There’s a role for that in the offense.
Again, he’s a backup big who might get 15 minutes a game against some teams sometimes. But those could be a very useful 15 minutes, helping to prevent another series like we had against Chicago last year.
The fact that Davis accumulates 50% more screen assists than Baynes tells you next to nothing about their usefulness in an offense by itself. Baynes is often off ball and not exclusively setting screens as much of the offense is ran off Horford. Davis has 1 job when on the floor in Portland and that is to set screens for McCollum and Lillard forcing his defender to help try to contain them, he can do nothing else. The guys who accumulate the most screen assists are not necessarily the best screeners, more often it is because they cannot do much of anything else and screening is their most effective/only usage. It is way more effective to have a Horford or K.O. to run your offense off of creating space, slipping/setting screens, popping, driving, spotting up and diversifying your offense much more. Horford doesn't accumulate as many screen assists simply because he does way more than just set screens.
With the Celtics severe lack of spacing when Horford is out of the game I wouldn't want anything to do with Davis nor would I want him paired with Horford clogging things up.