When installing a 20KW generator on a residential 400amp service using a 200amp rated transfer switch. We used the transfer switch outside to protect one of the panels by the generator. The inspector is saying now I need to add a 200amp disconnect outside for the other electrical panel so the disconnects are grouped. Is this correct or is there a code article I can reference that states an exception for a generator disconnect not being required to be grouped together? Any help would be appreciated.