Is there a formula or policy or requirement for how many contractors a COR can handle at one time?
I don't know of any such guidance. It would be difficult to establish such as standard because the scope of different service contracts can vary widely. A COR might be able to effectively oversee 10 relatively simple contracts, while the same COR might could find it difficult to oversee 3 complex contracts. This is yet another example how contracting officers must exercise good business judgment in the performance of their duties.