They are not a hivemind, after all they also suffer from intraclass conflict, as seen in the NATO-Russian war. But there are definitely interest groups, and we know since the mid 19th century that the class that controls the economy is also the class that shapes society as a whole. So no, it's not a conspiracy theory, it's sociology and marxism. After all, it's not crazy to think that the handful of capitalists who own the British press also defend their own interests through this same press.