I would not recommend it in the long run. While it depends on the temperament of the RD, the RD is likely to go after the mubana's, and the mubana's won't be happy with the RD not respecting their territory.
i keep africans with my rd and she ignores them, i said give them hiding spaces because they like their own Territory's, my rd kills everything else though
Even if you addressed the territory and hiding issues, the Africans and the RD require different water parameters. What you do to make the tank suitable for the Africans may actually be harmful for the RD. I wouldn't do it myself.