Well, I can't imagine the progenoids have much interesting in game effect. They are "only" there to absorb genetic material for the next generation of Space Marines. So probably more like 14.
Just realised how much the idea of progenoids make no sense... ok, "now" that the knowledge of how to make the Space Marines' implants (from scratch that is) have been been lost they are vitally important, but why create them in the first place? Surely you expect to know how to create them and so don't need some otherwise redundant organ whose sole purpose is to collect the genetic data from the other organs?