May have to revise here.
Roy's best back-ups in Montreal were Brian Hayward,Steve Penney, Rollie Melanson and Ron Tugnutt. Last two were very short term. The rest were rather forgettable. Some became bottom tier Quebec semi pro goalies.
In Buffallo Dominik Hasek had backups like Grant Fuhr, Daren Puppa, Martin Biron, Steve Shields, Andrei Trefilov - Olympic and WHC team member, Dwayne Roloson.
Martin Brodeur had Hedberg, Clemmenson,Schwab, Vanbiesbrouck, Dunham, Terrari.
New Jersey did the best job of picking appropritae backups. Hasek had the best in Buffalo, Roy the weakest in Montreal.
Well, let's get this right. Hasek was one of
Fuhr's (some might prefer to say Puppa's, I guess) backups in '92/93 (I'm sure they had been banking on Puppa developing further/faster than he did after his '89/90 season), and outright stole that job from him the next year by blowing Fuhr's numbers out of the water. 0.050 difference in SV%, and almost 2 GAA in difference. If you're strong in your convictions that Fuhr's level of play "contributed to Hasek having it the best", then you must be absolutely amazed by what Hasek did in his first year as an NHL starter behind the exact same team in '93/94. Granted (no pun intended), Fuhr ran into a few injuries that year, I think, but they won the Jennings despite Fuhr's 3.68 GAA over 32 games, lol.
On top of that, though, would be the problem of Rob Stauber "outplaying" Fuhr in '94/95 (after the trade, obviously) behind that same team again (even bigger statistical divide between them and Hasek that year), and both being shipped out by the Sabres at the end of that season.
So Biron and Shields are the only ones really worth mentioning (imo), and Biron wasn't even a real consideration until Hasek's 2nd last season as a Sabre. Fuhr was a name in the end, and not much else. Trefilov was possibly one of the worst goalies to ever play more than 10 games in the NHL. Roloson, for that matter, was about 2 or 3 years away from being relevant in any way, as it turned out.
More to the point though, I suppose, is that at least Montreal had Hayward's best years. Same could almost be said of Tugnutt, who hit his peak in Ottawa
right after his Montreal days. And Doug Soetaert played more games in the Patrick Roy era than Steve Penney, btw. You forgot to mention him... not that it makes a difference, lol. Melanson really was bad for a long time, but surprisingly Roy didn't absolutely statistically trounce his 9 games as a Hab (~0.030 diff. in SV%, 0.3 GAA). Heck, Melanson even earned 2 of his career 6 shutouts in those 9 games behind those '91/92 Habs.
In any event, just looking at your list, I'd say Brodeur had it the best based on Terreri alone. They also got some of Schwab's and Clemmensen's best hockey though, among those you mentioned. Add Beezer and Hedberg to the list of geriatrics who enjoyed statistical success behind the Devils of the (lengthy) Brodeur era for some interesting context.