I’m a big Garland fan and I’ve been praising him, but I don’t think 27 a night is realistic. Or optimal for the team. That kind of scoring territory is reserved for the absolutely elite scorers in the league who can do it from basically every level of the floor. I can definitely see DG getting that 3P% to ~40% in his prime. But he doesn’t get to the free throw line enough or score at a high enough volume at the rim (and physical limitations play a role here) to be THAT kind of scorer imo. He’s mainly a floater or lob guy inside, not a guy who can easily finish right at the hoop over length and through contact. And keep in mind only three players - Durant, Curry, Giannis - are at 27+ this season.
You can argue that Steph with a .215 FTr and a .143 rate of scoring within 0-3 feet, along with his 6’3 height, proves that Garland can be that kind of guy. But the issue is that Steph is such an extreme outlier with his shooting, it’s basically impossible to imitate. Garland is a great shooter who will only get better, but he’s not in the stratosphere of a Curry and never will be. And really no one is or will be for a long time.
To me, Garland’s ideal role will be as an efficient (60%+ TS) ~22-23 ppg scorer who also gives you 8-9 apg. That can absolutely be one of the premier offensive weapons in the league without him necessarily almost leading the league in scoring. I think Garland’s tendencies and abilities make a Nash lite-passing/Steph-lite scoring role a much more optimal fit for him.