Philadelphia Dawgs: This can have two meanings. As Philly is the city of Brotherly Love, I thought this nickname friends sometimes give each other could be fun. Plus, it can be used as a dog theme too, preferably something tough like a bulldog, rottweiler, or dobermen, to fit Philly's tough reputation.
San Francisco Miners: I know it's close to the 49ers, but the gold mining theme was all I had left after most of the best names were taken. It's still a solid theme to San-Fran's history though.
Minnesota Owls: It was either going to be this or Hawks, and I thought Owls would be a bit more unique. This would have the Great Horned Owl in mind, which has been nicknamed "The Tiger with Wings" by some.
Toronto Boars: One of Toronto's nicknames is "Hog City", and I wanted to use more animal nicknames anyway, (seeing as a significant amount of teams in real life do so). Boars have those tusks and just look like a tough/mean animal, so I thought it'd be a great hockey team theme!