I think he's a strong fit in DAL (a lot of the local guys there have talked about how they can't afford him, but the fit is actually decent), because what he can do there is be the secondary ball handler and a cutter, DAL's offense was a mess last year because they had no other ballhandlers beyond Luka, and were trying guys like Richardson in the role. With Simmons, you let him cook for the 14 minutes Luka isn't on the floor, and run a bunch of PnR and dives for the 20 or so they share, and occasionally set Luka off-ball to give him some rest and keep him fresh. And he lets you have someone else to run fast breaks, which will help their transition offense.
With GS, and POR, you're going to use him in the Draymond type role, when sharing the court, running offense from the elbow much of the time, screen and diving, and then being the PG for the bench unit.
I think you overestimate how much these guys need/have the ball. Even the most ball dominant players in the most ball dominant offenses usually only play 34-35 MPG and have usage under 40, you need other guys who can create off the dribble, and you need someone to stagger in for the almost 1/3rd of the game those guys are going to be on the bench. Aditionally, having the ability to sometimes shift those guys off-ball is helpful because it eliminates all the doubleteams they face. And on the other end, Simmons is unique in that he can handle most anyone making sure you put your defensively suspect star on the worst guy the opponent has.
