I think it's a fair point. Bruno did draw in Canada though. He was a mainstay for Frank Tunney, and shuttled between New York and Toronto for years.
The point is really that Hogan only worked as a national draw. Vince was also pretty smart with his TV appearances, kept him special, always made sure that the people wanted more Hulk and didn't get burned out on him. And even then they did get burned out by 92.
I don't know if you could go national with Bruno, but I do think he would have gotten over in pretty much any territory.