I mean what "goalie quality vs. system" argument can be made when some of the goalies who were in top-10 Sv%, some posted amazing stats (.94+), are Vladislav Fokin, Vitali Kolesnik, Sergei Borisov, Alexei Kuznetsov, Vadim Tarasov, Jan Laco, Mark Dekanich, Pavel Poluektov, Kevin Lalande.. The list goes on, those are from 2012 to 2015.
All these guys have been a) good for one season after landing on a good/defensive-minded team despite sucking throughout their career and being known as quite terrible goalies; b) while playing for the said good/defensive-minded team if they managed to stick for more than a year (Kolesnik). As you can see, it isn't necessarily the goalies of good teams. Some starters, some backups. Point is, "system goalie" is very much a thing in the KHL and although there definitely are some very talented ones in the KHL statistically they aren't any better than those guys. Look at Lars Johansson, never really recognized as a very good goalie throughout his career he, numbers-wise, outperforms Sorokin every season they have played together.
Very often, backups (who are obviously worse goalies than the starter) have the same, if not better numbers than the starters because well, obviously, those are the product of the team in front of them. Even if it isn't particularly good. Like Neftekhimik had ~.936 team Sv% in 2016, as another quick example.
And you can find the same examples on the offensive side of things. Lets take a look at 13/14 Donbass roster, for example. Stacked, stacked team. Kagarlitsky, Kaspar, Dadonov, Robittaile, etc. Kaspar with 36 points on the season is the leading scorer, everyone else is below 30. Goalies combine for, roughly, .938 Sv%. It doesn't take a genius to realize what's happening. And you can find it all over, top scorer on Ak Bars had 34 points in 2017, Loko was led by 35 points of Staffan Kronwall in 2018, etc.
And someone who has watched Bilyaletdinov's hockey for years saying "it's not a tactics thing" is just laughable. In case the eye test isn't enough, hasn't he said during the final series against MVD back in the day something along the lines of "if we score 1 5-on-5 goal and 1 PP goal we will win most games 2-1"? That's what so many coaches in the KHL are aiming for, hence 1/3 of the league scores 2 goals per game on average.
One could make a whole list of things that lead to that low scoring: the way teams break out, the way teams change, the way most teams don't use substantial net-front presence 5 on 5 to not get their guys trapped deep in the O zone, etc. Anyone will notice that if they pay attention.