Neither group is served by being represented by the same union. The regional system exists in order to economically oppress a subset of labor, it is the nature of things that the oppressed may not always have their master's best interests at heart, and vice versa. Fundamentally, that's the dynamic we're dealing with. Unity, brotherhood, etc is all lipstick on that pig.

If major pilot groups one-listed all their feeders, then problem solved. Easier said than done, but it's within the realm of the possible (unlike the national seniority list fantasy).