I think that all that the Marner/Matthews vs. Kane/Toews is looking at similar players stylistically and trying to make comparables. Honestly, you can see some stylistic similarities throughout the two lineups. Kane/Marner, Matthews/Toews, Gardiner/Hjalmarsson, Rielly/Keith, Zaitsev/Seabrook, Nylander/Hossa. Now, obviously the Leaf players aren't even close to the Hawks guys yet, but you can see that there's a similar play style between a lot of the guys. What it shows to me is the mold that the Leaf management is trying to make for their roster.
Personally, I don't think Marner hits Kane level. I do think Matthews can hit Toews level though. Honestly, it could be as early as next season. He's not a superstar yet, but if you watch his game, you can't deny that the talent is there to reach superstar level eventually - and sooner rather than later.