[usbcd36]

I see what you mean. <R52> says that motors not prohibited are those specifically allowed by <R51>, which says specifically permitted motors are the ones in the KOP among other things. This means that the motors your team received in its KOP are legal, not that all types of motors that come in the KOP are legal in any quantity.

While the logic is a little fuzzy, the intent is clear: you can use all motors permitted by <R51>, and can use no motors not permitted by <R51>.

One thing FIRST discourages is "lawyering" of rules; just because there's some slightly ambiguous wording in one of them does not mean you should try to pick it apart to gain an advantage. Besides, I doubt you'd be able to convince an inspector that your robot was legal if you did what you're suggesting.