I wouldn't trust the small-sample size data he's using yet.
While Granite has drawn an okay amount of walks in his minor league career, he wasn't elite there. (MiLB career .064 IsoD vs. .084 in MLB in 2017).
Granite is more of a Revere type to me, but certainly will draw more walks then Ben did. Has the bat control to make contact with pretty much anything he wants to swing at (which I think his data is saying more than he has elite "plate discipline"), but he's not going to draw walks like that moving forward.
I hope to be pleasantly surprised on that last part.
Scouting Report: Power: 30, Hitting: 50, Arm: 60, Defense: 45, Speed: 45. "Line drive swing and shows good contact and on-base abilities. Double's power at his peak. Strong arm from 2B or the OF, stiff hands. Not a fast runner, but above average instincts on the bases. Skinny body doesn't look the part, but will sneak up on you. ACL surgery sapped much of his athleticism." (Probably)