If I independently verify that subsystem A properly consumes apples, and that subsystem B is properly emitting oranges, but never verify that subsystem A is receiving apples, and just connect subsystem B to it, then yeah, the system is not verified.
you’re deeply confused but the words “validation” and “qualification” may help untangle the web, there’s a lot more to assurance than what your model seems to hold (and you’re drawing batshit deductions from it)
That's not the issue though.