Separate Army and Navy chains of command did not prevent local cooperation in the defence of Pearl Harbor. The distinction is between the Pacific-wide naval commander and the local naval commander responsible for the base. Coordination with the Army's local defence forces belonged at that lower level, with meetings and communications between the relevant units. Looking only for a direct link between the Pacific Fleet commander and the island's Army commander can therefore miss the headquarters whose job was to provide that connection.
Notable Point · 5:51:08-5:53:16
Pearl Harbor's local Army-Navy command links
The command hierarchy explains why separate service headquarters do not establish an absence of local cooperation.