If you say you have the best centre depth in the league you are talking about right now. So even mentioning Marleau is irrelevant. TO has Tavares and Matthews and if you don't consider Matthews a top level talent you just hate the Leafs and there is no point in continuing this conversation. Backstrom and Kuznetsov are great as well, I'd put Kuznetsov in the top 10 even. Backstrom is not bad either.
Two years ago when Backstrom played with Ovechkin and Oshie, he was third in points among centers. Kuznetsov, playing with Justin Williams and Marcus Johansson, was 17th. Last year, when the Caps spread out their offense across three lines like Pittsburgh does, and Backstrom played with a ragtag bunch of whoever was available until he got Oshie back for the playoffs, he was still top 30 among centers in points. I'd put each among the top 15, but it's so hard to say either is top 10 on their own when you have to factor in Ovechkin.
This year, so far, I think Matthews is way better than Tavares (16 pts in 11 games vs 17 in 16? And Tavares got the good wings?), but if Matthews stays out a couple more games, and Tavares keeps getting the ice time he's used to, Tavares is going to climb back into the top ten centers in points. Both are top 20 right now. Matthews will keep improving.
By points so far this year (way too small of a sample size to matter) Toronto, Washington, and Calgary each have two guys listed among the top twenty centers (but one of Calgary's plays a lot of wing?). Edmonton has three listed, but again, one plays mostly wing.
If you look at last year's playoffs, the Caps had the top two in points, and Eller was 6th, but that's easy when you play more games, on the strength of great clutch goal scorers like Andre Burakovsky (?), Alex Chiasson (??), Devante Smith-Pelly (???), and Brooks Orpik (????!?!?!?!?!?!?!!).
Watching the Caps play the Oilers the other day, Edmonton's a really fun team to watch. They move the puck around really well. They understand the cycle game, pretty well, on three lines. I think Strome is underrated among Oilers fans, for his vision and playmaking skill. I also think the team's game plan of having one wing on each line just go to the net and chill is not great for helping them keep puck possession in the offensive zone. They should acquire some speedier, more skilled wingers, and/or get more use out of the ones they already have.
People talk about the Caps as a team with big guys who can create space in front of the net, and that's true, but those big guys don't just stand there when the puck goes into the corner, hoping for a lucky bounce. They go skate and try to get the puck. Sometimes it works.
I don't think any team has a 3C better than Kadri right now, that actually plays 3C. If the Leafs ever get a third RHD, they're going to be pretty good.