Other than the SNL connection, I don't see how Fallon and Meyers are all that similar.
I'm not a huge believer in Fallon, though I liked him in Fever Pitch, but at least Fallon in my mind seems like he's used to the whole song and dance and doesn't come off as a tryhard. Watching Myers though, he could be really funny if he had presence, but his delivery is so bad I cringe everytime he tries to make a joke. He's like a kid wandering onto his high school's talent show for an open mic and waits for that elusive laugh everytime he tries to make a funny.