You can't really fault a prospect for an opportunity they never had, which is why Lamoureaux is ahead of Koly despite being three years younger. The upside is just higher, even though there's a nonzero chance Lamoureaux never makes it or never makes it out of a bottom pair specialist role.
Remember the old HF ranking system of a raw number+a letter that indicated the likeliness of reaching their potential? It's like that. GMs are also not looking for replacement level players in trade. They want as much raw upside as possible.
So while there's a good chance Koly will be a solid roster player for years ala Schlemko, teams are not likely to ever dream of trading for him at his current level. Just the same, Duda can end up in a bad developmental spot or simply fail at the next level of competition, potentially ruining his trajectory. Put another way; Duda has a greater chance of being a bluechip but has less track record, so the risk (variance) is higher.
I really would have liked to see more than 3 points in 32 games out of a guy who skates like Koly TBH.