As a structural engineer, I’ve tried to avoid commenting on to the North stand threads. Without seeing the reports, knowing the structural form, details and defects (and ideally the condition first hand, plus also potentially doing some analysis) it’s hard to give any helpful comments. However, to provide some completely irrelevant comments on a hypothetical situation - whilst technically what you are saying could be true, given the age of the north stand it is unlikely to have been designed this way. As long as the roof bracing remained in place you would probably be able to remove the roof sheeting without causing notable undue issues with loading to the cantilever structure. What is possible however, is that if there are other defects of a substantial nature that have caused loads to redistribute somewhat, the roof sheeting could be providing some diaphragm action against wind loads.