perimeter scoring is primarily per, bh, and spd dependent, with the standard iq/fatigue (stamina) inputs.
someone who coaches d3 should probably contribute, but i'm thinking for your level of d3 guy, that guy with his 81 per and 60 spd and 51 bh, is good but not great. he looks like a guy who should at least be +1 but you could also do +2 depending. still - there's a couple considerations in the +/-.
one is how much you need 3pt shooting from that guy. looks at your team, i sort of feel like you'd have a decent amount? its only 3 games though, so its hard to tell from the stats - but right now you are taking 25% - which is low in general and you want that to be higher. i feel like in general in this game you want to be in the 30s, and if you are sort of like, working your way up, really the higher side more than the lower side. but you mostly want to try to play what is 'natural' for the team and then adjust up/down if you are out of a reasonable range. 25% is too low in general and too low for your amount of per. but like i said... 3 games - no idea what you are really doing.
another consideration is the player himself. not all players at 0 will shoot the same. if they have more per and less lp, not sure its quite that simple but more or less, they'll take more 3s. if they have more ath/lp, they'll take fewer. your guy is a pretty heavy per-based guy and he'll likely take a bunch of 3s given his setting. still, i wouldn't really consider anything below +1 for a guy like that. 3pt scoring is slightly over strong in this game, it used to be more, but it still is slightly. so you generally want to utilize your 3pt scoring pretty well. there is really very little 3pt% penalty for going from 0 to +2, like, very little. i think you perhaps get a little boost on a -1 or -2 because the player is like, more selective or whatever (the sim engine doesn't exactly work that way, but its not unreasonable to think of it as such).
in summary - at least go +1, and watch your team 3pt attempt % (3pta/fga) and make sure you are up there around 35% or so with this team. adjust up if needed. frankly, your team looks like one who should be on the higher end of that 30% range, 38%, maybe even 40%. its been a while since i played d3 (more than a decade) but the only real danger in going 40% and higher is that smart coaches in the NT will game plan against you. but you are a newer coach rebuilding, and that just isn't really a concern right now. those other three 70 per guys i think can all easily go +1 as well - i'd probably do +1 for all them and +2 for the 80 something guy, but it might end up being too much 3pt shooting (although really, im not sure there is such a thing when you are rebuilding a d3 school!).
good luck!