This man is correct. Both shows should be of equal standing. I wouldn't go for a complete "Brand Split", but the GMs should converse regularly in order to avoid scheduling conflicts. Think of it like UFC - They don't blow all their talent on the same card, they spread it out.
For Example, say we've got Aries vs Pato on Riot, then neither Aries or Pato are eligible to wrestle on show B that week. It'd take a sit down to work out who the GMs consider main event, midcard etc, but as long as they work together, there's no reason why it shouldn't work. As far as RPs go, if you're booked for a show that week, then do all your content for that specific show, rather than submitting loads for riot, then loads for show B.
Think of it in real life terms - if you're not physically needed in the building to wrestle (unless in rare instances for story progression, you're involved in a match or whatever), then you wouldn't be there. Obviously, this is only possible if the roster stays as active as it currently is.
Dunno if this'd go down well, just thinking in forum form