Your basic premise is accurate and is an interesting dynamic to watch for this tournament: Canada’s D isn’t the usual 800 pound gorilla on paper, and Russia’s D is the best its iced in a long time. When you factor in the goaltending situation, this will go a long way towards leveling the playing field between the two countries.
However, despite all of that, I still think you are underestimating Canada’s depth of quality D. Orlov would not be in the conversation to make Team Canada at all. Provorov would be “in the mix”, but Canada’s depth at the position is still incredible. There are 12 or 13 guys in the mix around Provorov’s level. They could ice 2 squads worth of players at that caliber. The weakness has never been and will never be depth of #1 caliber defencemen. The weakness is, as you also shrewdly noted, the lack of their usual cohort of a proven ultra-elite top 4. Canada will never have to use a weak defence man at any time, but they usually have at least 2 pairings full of legend-caliber D and they will not have that in this tournament unless younger players like Ekblad, Makar, Chabot etc step up the way Doughty did in 2010 and establish themselves at that level in this tournament. It is possible, but usually Canada has Bonafide established HHOFers at the top end, while the best players on this roster will be challenged to establish themselves at that tier. Interesting dynamic to watch, but Canada’s B Squad of cut players will still be totally full of #1 D men - Orlov would not make it.