Nor that the other, supposedly surviving five aren't
controlled by the Borg. We haven't seen anybody else make use of the network but the Borg themselves and of course Janeway.
We don't know how many Queens there are, but one would suffice to explain all the appearances. How many bodies this one Queen has at any particular time is another question: the bodies she uses appear to be cloned or otherwise series-produced so that two types (Alice Krige and Susanna Thompson) alternate, but this sort of implied that there exists an endless stock of Krige and Thompson bodies, and the Queen might simultaneously reside in hundreds or millions of those at any given moment.