Vonleh's best comparison is Favors. Take a look at Derrick's college stats:
https://statsheet.com/mcb/players/player/georgia-tech/derrick-favors
Both are drafted on potential: very young bigs (both turn 19 right after draft), extremely athletic, had ok seasons for their clubs with similar stats without making much difference in team's performance nor helping their teams do well. Volneh seems to have good outside shooting ability, which might (or might not) be developed into a weapon, and Favors is a little bigger and better shot blocker. I think there is a good probability Noah will become a solid starting PF/C in NBA, bringing athleticism and defense, which is very important, but not sure it is very likely he will be a star difference maker. Probably a solid #5 pick, but nothing to get overly excited about, especially since we already have Favors on the roster.