Are Fournier & Richardson really that drastically different when it comes to "playmaking"?
They average virtually identical assists for their career (including both being at 4.6 per 100 possessions).
Also, Fournier is a 38% career 3 point shooter & JRich is a 36% career shooter. Fournier shoots better at 2s (50%/48%) & shoots more, but JRich has hit more free throws (83%/81%).
You can certainly say Fournier brings more gravity because he shoots slightly better & slightly more (per 100 possessions 2.6 more fga & 1.4 more fta), & carries a higher usage (22/19) but I don't think there's some huge night & day difference between their offensive games.
In the playoffs, they've both been terrible & shot 37%, but JRich has been slightly better overall.
To the extent that creation is something the Celtics need more of, Fournier isn't really that guy.
Defensively, Fournier is kinda rexy & blocks shots at 1/4 the rate JRich does & doesn't really cause anyone any problems. JRich is probably overrated defensively, but a lineup of Smart/JRich/Jaylen/Tatum/TL seems super fun.
All else being equal, I would pick Fournier, but all else isn't equal - 1/$11.6m v. 4/$80m (probably), so it seems like an intelligent choice.
https://stathead.com/basketball/pcm_finder.cgi?player_id2=richajo01&player_id1=fournev01&sum=0&request=1