Maxey is an interesting player, but perhaps also very similar to Langford (I guess better playmaking and a better shooting form, but Langford has more switching ability on defense).
I'm intrigued by Precious Achiuwa (and packaging #26 + #30 for him would be a no-brainer for me).
A future starting frontcourt for the Celtics of Achiuwa/R.Williams could be incredibly dynamic and an absolute terror defensively. Both guys can protect the rim and switch to cover smaller guys on the perimeter, while also having a decent handle for bigs. Lots of work to be done for both of them improve offensively, but with Timelord's passing ability and Achiuwa's driving ability they don't have to be useless outside the paint.
I believe Maxey can be developed into a PG or at least a PG in the Jason Terry mold. He maybe best suited playing secondary initiator to a primary wing like Tatum. His over lap would be more with smart than Langford. While Smart is the superior passer and defender Maxey should be a better penetrator and a more consistent shooter.
Achiuwa and R Williams would be a spacing nightmare. I like Precious but only if he is drafted to play center. He was initially miss cast as a swing man at Memphis. When Wiseman was suspended Precious showed his true potential as a Faried like center. He could ultimately be a Theis/R Williams hybrid big man. His appeal is the fact that he can hopefully rebound at an elite level, punish other bigs off grab and go fast breaks, provide some rim protection, and switch 1-5
Achiuwa has a low BBIQ and he has poor fundamentals. His highlights are not his real game they are the times he got it right. He doesn't have the mental tools to go with his physical gifts. In a different draft maybe take a shot but there are more compelling alternatives at PF/C. He is the type of player that bad teams draft high and thats why they stay bad teams.
I'll admit I only got footage of Achiuwa on highlight videos and some short scouting videos.
He looks to be athletic and engaged enough to be able to guard positions 3-5. That switchabilty and the ability to protect the rim is something the Celtics can really use. Brown and Tatum are excellent wing defenders, but also a bit small when having to guard the best PF's in the game like Antetokounmpo, Siakam, Adebayo or Davis.
Achiuwa looks to have the right frame, athletism and mentality to become an elite defender. He's an excellent rebounder (a skill that often translates to the NBA) as well. Offensively, shown in those highlight videos he has creative moves to finish and doesn't just rely on athletism and size advantage on college players.
But if you say those highlights are outliers and that he has poor awareness and BBIQ I believe that.
I love Robert Williams and without his injuries he probably would be a much more talked about prospect, but despite all his great defensive plays and ability his advanced numbers on defense aren't any good (compared to for instance Theis). Such type of players just need experience to do the simple things right.
One note, I believe that when we talk about spacing (I suggested a future Achiuwa/Timelord frontcourt) we don't talk enough about vertical spacing. A guy like Javale McGee, who really has a low BBIQ and doesn't have any ball handling skills or post moves, has been very valuable for the Lakers and the Warriors because as an offball vertical spacing provider he has a useful role on offense.
Too often the Celtics offense is predictable as a purely inside-outside game based on drives to find open shooters. To really compete for a title we need more dimensions on offense.