Firstly it’s very important no matter the level that your team wins it’s home meetings or at least enough of them to keep the crowds coming back, it doesn’t matter if the get a hiding away from home because very few fans actually travel now so unless you pay for a stream, you only see your team when they are at home.
Secondly whilst the idea of a promotion being run by members of another seems odd, I know from reading the history of the sport, there used to be promoters who ran many tracks at the same time so it’s nothing new.
The basics of speedway as a promoters is always, put together a team that will win most of its home matches and provide a track that will suit those riders and doesn’t leave your patrons covered in dust.
I used to go to Rye House on Sundays afternoons every so often, especially when they were in a different league to Arena, I don’t remember many occasions if any where on nice warm afternoon, I would get covered in dust.