Since there is no user accessible bass management as part of the speakers, my opinion would be to consider them just full range speakers and not as separate subs and therefore, they would not be counted as subs if you are adding new subs to the system.
However, there is not quite enough information to answer this question fully. What else is in your signal chain? How do you plan on hooking the additional subs up to your system?
However, there is not quite enough information to answer this question fully. What else is in your signal chain? How do you plan on hooking the additional subs up to your system?