I'm not sure that Ryan's potential is that much higher than Kadri's.
Tough to say, but I'll take the bigger guy who has equal/better numbers at every age throughout his career. It's only this year that Kadri was pretty even with Ryan's numbers at 18/19.
The fact that Ryan has the size makes me a bit more comfortable with his potential in the NHL. That said, Kadri could be a superstar and be way better than Ryan... size isn't the be all end all.