Brodus Clay and Tensai are fine as a tag team and don't need a manager. They have good valets. Tensai is too old to be anything more than a tag team guy, and Brodus is too young and needs some more experience before he adopts a more serious persona.
Bo's still in developmental so he doesn't count yet. And he doesn't need a manager, he's annoying and has gotten the crowd to hate him all by himself. Ezekiel, Hunico, Camacho, and JTG probably won't be resigned so why bother? DiBiase Jr. could use one. Kidd just needs to get Nattie back as his valet. Hawkin's is a jobber - thus doesn't need a manager. Drew and Zack don't need one either. Otunga is seemingly no longer a wrestler. If/when he returns on TV, I doubt e'll be used as one too often. He's better solely as a character.
But since he's no longer GM, I'd love to see Booker T become a manager. Maybe for the Primetime Players since they're babyfaces now. If pushed they can turn heel again one day by aligning themselves with Teddy and dumping Book.