Sorry but as good as sundin was , he isn’t close to Matthews in my opinion.
Sundin had to be the one man gang, he didn't have an elite passer like Marner or even a great passer like Nylander on his wings. Sundin was a 1st overall pick, he had a 114 point season when he had great players on his wing in Quebec.
Matthews is definitely one of the best the Leafs have ever had, but then don't forget Gilmour, Sittler and Viave (I don't go pre-1974).