I know GNE are ditching brands, but except for flagship routes, but i had an idea, why not just have 1 area brand aswell as flagship brands, i'll pick Durham (because its the easiest)
So you'd have the Angel 21 and Prince Bishops and thats it, the X21 could be a branch of the Angel Brand, this is more of just a thinking out loud, so dont take it literally, suggest your own