Wasn’t it all the same studio in the end though?
Cloverway wasn't a studio, but a "middleman" company for anime distribution in the Americas.
They were like Toei's right hand in the USA before they had HQs there, and when DiC didn't show interest on S/SuperS, they took over the distribution and hired Optimum, a Canadian post-production company, to produce the Sailor Moon dub, just like both DiC (previous seasons) and Pioneer (movies) did before.
But Cloverway usually wasn't in charge of English dubs. This was usually provided by the NA anime license holders like FUNi with Dragon Ball. On the other hand, they produced the majority of Latin Spanish and Brazilian Portuguese dubs for Toei products until like 2007, when Toei themselves opened headquarters in Latin America. They usually hired studios in Mexico and Brazil for the task.
I know, it's confusing. For some reason, Bandai's local representatives (!) produced the early Brazilian dubs of Saint Seiya, Dragon Ball and Sailor Moon before Cloverway also took charge of distribution in Brazil.