Head to head, the SV% of Fleury/Murray & Holtby is roughly equal except in 2017. In 2017 Holtby single handily won the Pens the series against the Caps.
2017:
Fluery: SV% .921 on 229 Shots against
Holtby: SV% .887 on 151 shots against
Fleury faced much greater offensive pressure(78 more shots) and badly outplayed Holtby when it mattered. Reverse the performances between those two and Sid Ovi have two cups each.
Crosby has had his share of bad luck, but he definitely had a lot of luck when it comes to his teammates stepping up when it matters and his team winning out despite being dominated.
This may be the worst taking point in the whole thread which is saying something. It is a lot more reasonable to say that if you gave the Pens the Caps goaltenders they would have won even more Cups.
Years in which the Caps starting goalie was statistically superior to MAF in both sv% and GAA in the playoffs:
2009 - In the Caps/Pens series, Varlamov was better and the reason why the series went 7 games when the Caps were outplayed most of the time
2010 - The Caps got Halaked, the Pens got MAFed in Games 6 and 7.
2011 - The Crosby/Malkin-less Pens put up a better fight against the Bolts than the full roster Caps
2012 - MAF was legendarily bad that year, playoff rookie Holtby beats legendarily great Tim Thomas and matches legendarily great Lundqvist.
2013 - MAF gets replaced in the Pens 1st Round series vs. the Islanders after a Game 4 that was argubly the worst game by a starting goalie in the 2013 playoffs. Vokuon takes the reins the rest of the way and puts up a .933 sv% and 2.01 GAA vs. .889 sv% and 3.51 GAA for MAF. Holtby, who by this time has taken the goaltending reins as much as MAF had for the Pens, is solid and loses due to Lundqvist
2015 - Holtby lead the playoffs in sv% and GAA (min. 5 games), MAF is solid vs. the Rangers but not good enough
2016 - MAF has been replaced by Matt Murray but starts one game and loses. The Caps get good enough goaltending from Holtby to beat the Pens but they lose due to the Pens rolling three scoring lines to the Caps one.
2018* - Holtby outplays Murray in the 2nd round and gets Smythe recogntion
Out of
ELEVEN seasons, the Caps had better goaltending
NINE times.
From 2007 to 2017, out of 17 goalies who started 40 playoff games,
MAF is 14th in sv% and 16th in GAA.
From 2012 to 2018, out of 22 goalies who started 20 playoff games,
Holtby is 2nd in sv% and 3rd in GAA.