I don't know Pacific but I'll take a shot at the Celtics.
They are all in on next gen stats using spacing and talent to focus the offense almost exclusively on 3 point shots or dribble drive attack the rim. You can see that in their
shot chart from Game 7 Yes they will shoot some mid range shots but that is generally at the end of the clock or when they find the lane crowded and no kick out. IMO Brown and Smart shoot most of the mid range. That is the 20K foot view but I think the important view is to look how they run with and without Horford on the court.
Horford is a 40+% 3 point shooter. Highest on the team I think. With him they generally park him in the corner as a stretch 5 and pull the opposing 5 out of the paint simply on the threat of his shot. He will drive the close out but the key element is the threat of the 3 causes the lane to generally be clear or he is open for a kick out. So they run almost exclusively a 5 out set with Horford in the corner and other guys setting picks to get either movement or matchups that they exploit. Tatum (or Brown) is more of a point forward in this offense and they really don't run a PG focused set. I won't go into any specific sets as we don't have a Horford and as such won't be mimicing the Celtics 5 out look - at least not immediately.
For next year it is more instructive IMHO to look at the Celtics when they have Robert Williams in the game. 6'9" 230 lb high energy/high motor who plays a lot like a bigger even more athletic Franklin. Zero 3 point shots for the year and an average of 8 PPG on 71% shooting. Definition of a player you don't run a play for. Also only shot 61% from the FT line so no idea why he ever saw the court
What you see with him looks a whole lot like the 4 out we ran with Franklin at the end of the year after we dumped the modified princeton - but with a bit more emphasis on creating mismatches especially in secondary transition. A lot more options than this but conceptually Williams will look to set an early high (past the top of the key) ball screen to see if he can either force a switch or beat his defender on a rim run. He generally then goes to the dunker spot while the perimeter 4 run their action looking for a dump off. He can come back for a second ball screen on occasion. I don't recall seeing him set a lot of off ball screens. Could be wrong there. He definitely is not a facilitator and rarely gets the ball except at the rim.
While I have focused on the 5 as I think that is what will be the limiting/controlling aspect of the offense, the key to the Celtics is obviously the talent of Tatum and Brown. Both of those guys can simply beat their guy off the dribble and get a shot pretty much whenever they want. So the Boston offense IMHO isn't so much focused on getting them open clean looks off of lots of off ball movement and screens instead is focused more on generating switches on these guys till they get the matchup they want and can exploit. Then it becomes dribble drive and lay off to the dunker or kick out with 2 rotation passes to an open 3 - but the key is the dribble drive. It is conceptually different than say the Golden State offense which is much more on off ball movement and screening but also has a Draymont Green who can facilitate from the mid post.
I fully expect us to go with one big and 4 perimeter players and look a lot like Boston with Williams. A lot of focus on causing switches and mismatches - One of the things I think we were bad at last year. I will be really interested to see what wrinkles he puts in as we obviously don't have talents like Tatum and Brown and our guys will need some help to get into position for shots or to create dribble drive opportunities. That will be the chess game for him.