I think O'Connor has a lot of the qualities needed to have a really high ceiling. I'd have him even with Hogberg in that regard tbh. I don't see the same with Hammond. That said, I'd say goalies are the hardest to predict in terms of likelihood of reaching their potential.
As for where you ranked them as of now, I totally agree, though my viewings of Hogberg are limited, so it's hard to compare particularly across leagues.
I think that's a pretty high benchmark. Over the last three seasons, no goalie has played 50+ games and had a .920 or higher sv% in all three seasons, and only 10 have done it 2 out of the 3 seasons. Only four goalies have had 2 60 game seasons with a sv% at or above .920.
Only one goalie has played 60 games all three seasons, only 11 have done it in 2 out of 3 seasons.
The reality is, goalies only need to get you to the playoffs, and then be good there. Quick has only met your benchmark once in his career, but I'd take him over Luongo come playoffs.
Wrt your point though, I think O'Connor is a longer term project than #1 goalie by 2019. Best case that's when he starts pushing for the role imo, so I get the sentiment.