The problem with a shorter goalie is they rely on technique and quickness. If one of those goes slightly off the rails, so do the results - see Saros.
Saros is in the 5'9-10 range, his worst season is a league average 901 sv% (33/67 goalies who have 10+ games) on one of the worst teams in the league. Again if height were such a big advantage for goalies, how is he not clearly the worst in the league with his massive handicap and how is someone like Fedotov managing to put up 876 at 6'7 or even some of the other bottom goalies in the league who are in the 6'3+ range?
Clearly being below 6' nearly DQs you from the NHL (hence why so many goalies lie about their height despite being 5'9, 5'10, 5'11) looking at the 2% draft rate in the last 10 year of sub 6' goalies, yet looking at some of the atrocious goalies in the 6'3+ range and some of the all time legends in the sub 6' range, there should at least be more parity.
One thing you can guarantee about a short goalie is they're going to have heart, some of the monsters have just the opposite trait of getting by on their size, getting shot after shot just due to their height when I don't think that should be the case at all.
It's interesting that we may never see an official 5'8 goalie in the league ever again, yet you can bet your bottom dollar year after year you will find 6'2, 6'3, 6'4, 6'5, 6'6, 6'7+ goalies putting up 840-880 sv percentages.