Another factor is that even in his prime Marty wasn't the best of his era - Hasek was AMAZING and Roy was better as well. Hard to say the best ever when he wasn't even the best of his era.
Marty is the Emmitt Smith of hockey - excellent but overrated because of his supporting cast that would have made anyone look great and someone great look exceptional (which he was not). He's still a special player - but if you look at pure talent he has nothing on Henrik IMO (save % is a more telling stat and Henrik at .920 vs. .912 is closer to Hasek's remarkable .922). Just like Barry Sanders and a HOST of other backs are superior to Emmitt.
So if health is on his side he's at least in the same top 10 conversation - if he wins a few cups he surpasses Marty. Wins alone doesn't dictate greatness.
martin brodeur isnt just the greatest goalie of all time, hes one the greatest hockey players of all time. he has gretzky like numbers compared to others, almost all notable records etc. in my opinion hes underrated compared to what he has done. rules had to be changed cause of his puckhandling ability, thats definition of greatness.
hasek was good but he "benefitted" of that system he played behind. u can check stats for hasek and he has clearly 4 year period he played for 3 of them for red wins and 1 for sens and that 1 sens year middle of that period he recorded a sv % of 92.5 when his 3 red wings seasons avg was 90.7 because he didnt face many shots as he did with the sabres and sens. same happened with luongo when he played for the panthers in early stage of his career, had his career high sv % and after he went to canucks, he had still decent numbers and got nominated for hart and vezina etc but never had that high sv %. so its easier to get higher sv % once u face more shots, its proven fact since if u face 35-40 shots a game, there aint 15 breakaways, dozens of 2v1's or 3v1's etc. most of them are blue line shots without traffic or just dump ins for hoping possible rebounds etc SO WHAT A SAVE THAT WAS!!
u are also forgetting the fact that in todays NHL theres 10 guys having 92.00% when it was 90s literally just a few guys even we had one of the greatest hockey goaltender era ever. they didnt even count sv % 80s or something, not really sure when some stat freaks wanted something to do and they added that stat there.
also martin brodeur has the highest sv % of goaltenders who has played over 1250 games in the NHL, 91.3%. highest GGA of goaltenders who has played over 1250 games in NHL 2.24. most shutouts, most minutes played, most games played, most shots saved, most this, most that etc. all that is just definition of dedication to this game. u cant play this long, literally being 15 years in his prime and 20 years of pure excellence without being an excellent goaltender.
henrik is a great goalie, one of the best in the league but u should not even put him in same sentence with marty(atleast in this stage of his career, 9 seasons played) thats just too disrespectful.