If you're signing 8 figure contracts based on non NHL success, longterm thats a losing game as a GM. It gives some context to him as a unsurprisingly good player, but really the only production you can directly value is this past season.
I mean Kaprisov only had 3 points in 7 games in his NHL playoff career. There are avenues to argue Kaprisov over Marner but I don't think playoff production is the way to do it, even considering Marner's horrendous showings.
Too bad Columbus was so stupid to walk Panarin right into UFA vs locking him up into some UFA years. Kirills stats and performances in the KHL demonstrated ample hockey bona fides. His NhL success was a surprise to no one that followed his career.