The problem I have with your suggestion is not with the credibility of the names you listed. Each is fine in their own domain. Rush was a true broadcast professional and instinctively knew how to grab and keep an audience. He took the intricate details and back stories of the political scene and boiled them down and presented the truth with great clarity. He made it look easy but it is not. That is why he sits at the top of Mount Olympus of American orators.
I have listened to Mark Levin present conservatism on his show for quite some time now. He is brilliant and smokes out the Left from his own perspective on a par with Rush, in my opinion. I think the conservative cause could and would rally behind him in a manner similar to Rush. Just my opinion.
Levin’s voice is like fingernails on a chalkboard. I really can’t stand to listen to his bursts of rage. The only time I tune in is when he is interviewing someone of interest. Secondly, Rush was a Christian, and while he did not talk about it, the essence came through. Those principles are what the Constitution was founded upon, and we need to preserve a core of Christian thinkers, even though the left has purposely used immigration to marginalize the foundational people, creed and philosophy.
To try to replace an uniquely singular man with another man (or woman—please, no) is going to lose many regulars. No one person is going to be able to step up to Rush’s level of output any time soon. You’ve possibly seen this in business, when a uniquely talented and productive employee finally becomes so threatening to the boss simply by doing his or her best, cheerfully, that the boss picks a fight and gets rid of him or her—and then it takes three or four people to replace him or her.
If the format changes to “all conservatives, from a variety of voices”, the variety is more likely to hold the most of the audience, and continue to attract more listeners as older ones fall away.