The question has to be asked the other way around in my opinion.
It was clearly answered in the past and for most corporations it is clearly defined who can take which advertisers and consultants.
But I found nothing about Cartel, Brotherhood and the Dark Eden tribes. I think they are all special cases.
The Cartel is independent. There are two possibilities: They can use all members of the Cartel (Capitol, Bauhaus, Imperial, Cypertronic, and Mishima) or none. Maybe they could take the tribes and Brotherhood, too. But ad least the Brotherhood sounds strange for me.
The Brotherhood is similar like the Cartel. They are totally independent but no member of the Cartel. Do they have advertisers and consultants at all?
The Dark Eden Tribes are no part of the Cartel, too. Do they have advertisers and consultants at all? Can they take the corporations as advertisers and consultants?