Another similarity between them will end up being that they were not properly appreciated by this fan base until they were gone.
You gotta remember that when Sundin came to the Leafs we had Gilmour, Clark et al. By the time those guys left and Sundin took their spot as the top player on the team his work ethic was not up to snuff or on par with Dougie's and Wendy's. A lot of fans were disappointed with Mats because honestly during the playoffs he'd be invisible for a game, or hurt his finger and sit out an entire series while guys like Roberts, Tucker, Mogiilny were playing with far worse injuries.
For me personally, Sundin was my least favourite Leafs captain because of this, and I know a lot of other Leaf fans that are in the same boat. Years went on, a younger generation of Leafs grew up watching Mats score big goals, but never any playoffs. So, a lot of the Leafs fans that grew up watching this team during his tenure when we never made the playoffs have nothing but love for Mats. He was always the best player on those very bad Leafs team, he was always the most "clutch" player on those very bad Leafs team. They never experienced a Leafs team that had better overall offensive/clutch players than Mats.
All of that said, comparing Mats to Phil is like apples and oranges. See if Mats was a right winger, and was simply there to produce goals as oppose to captain the team - he'd have much more respect from the overall fanbase.
Phil does his job well. Most guys that score a lot of goals are minus players. See Ovie this year he's in a -40? -50? A guy like Phil needs better overall support (see our weak defensemen).
That said - if Phil was the captain of the Leafs he'd be less respected than Mats was.