I can only speak for myself of course, but I would be happier with 5 man teams and one league. I've never really cared if the top stars are riding, it's not the names that make me watch speedway, it's the atmosphere, noise, chaos and racing.
I don't care if it's Bartosz Zmarzlik and Brady Kurtz racing or Simon Lambert and Drew Kemp. You make your own stars of the riders you watch.