Clarification on 'Deputy Ministers' - In functional, legal and constitutional terms, each ministry, for better or worse, is largely an autonomous affair. From that point of view, a minister can choose to have a deputy, not to have a deputy or appoint as many deputies as said minister desires; each ministry being largely self-regulating with the exceptions of constitutional or legal conflicts. In theory, a minister could appoint a block of cheese as a deputy (how a block of cheese could have enough sentience to do anything is questionable, but that's beside the point).
Technically speaking, deputy ministers not even being mentioned in the Constitution or Legal Code, could be anyone or anything, citizen or not, RA member or not as both documents are silent on the matter as to whether or not such 'government officials' in a largely autonomous and self regulating ministry should or should not even be a citizen. This gets even more complicated given the fact that there is nothing in the TNP Constitution that is declarative of whether or not the Constitution is a document that defines authority in a delegated and/or reserved fashion.