True Pontius. I think you make a very good point about dilution of effort. Also the snag for SACLANT was exactly that - he would not have had his own dedicated force, but would risk diversion to another theatre. Having your own organic force under command is much better. Naval airmen understand naval problems.
The apparently lesser threat gets sidelined by focus on the 'main 'threat'. All organisations suffer that. The RAF showed that before WW". Notionally in charge of Fleet defence, but that got ignored becasue of the much greater threat.
(Note - I'm not bashing the RAF here. This is normal behaviour, hard to avoid. It's one reason why the Captain of HMS Sheffield decided to abandon ship so soon - he was distracting the Task Force)