Dude, Guhle himself has question marks. He’s a top-4 NHL D, but it’s very much up in the air how much more he’ll improve.
Some D take longer to develop, some hit their potential early and stay there - e.g., Doughty, Hanifin, Ekblad, Pietrangelo, McDonagh, etc. In fact, I’d say it’s more common for good D to get there early and maintain rather than late bloomer situations, although both happen regularly.
We really don’t know for sure, but there’s really no indication that Guhle is going to suddenly become an offensive D; that’s just not his game. And I’d say it’s pretty likely that at least one of these guys will become far better than Guhle.
Guhle is a solid young D, but doesn’t and has never looked like he has franchise D, or even true 1D potential. Pretty much all these guys have that, or they wouldn’t be ranked where they are.