I'm not sold on either end up as more than okay rotation players. I think you need to check at least 2 of 3 boxes to be a high level role player/fringe starter in the NBA. Shoot, Defend, Passing Vision. Neither shoots well yet, Gradey is way closer to being a solid shooter though. Ja'Kobe is a terrible shooter at the moment. Neither defends well at all, I'd put Ja'kobe as having the better tool set to be a plus defender down the road. But neither moves the ball well at all. If the ball is going to stop when it hits your hands in this NBA, you better be able to fucking score. Neither will ever be that level of a scorer imo. 9-10% assist rates just isn't going to fucking cut it unless you defend your dick off and are a knock down shooter.
For comparison, look across at Luke Kennard tonight. Just a bench guy, that Memphis has allegedly offered up for trade all year because they don't want to pay the the 13-15 million he's probably look at in free agency...49% 3 point shooter, 19% assist rating. I'm not sure if either of our kids will end up better than the mid rotation guy that Memphis wants to move on from.