Spheroid - your examples are not quite the same thing...
Seems to me that your argument could extend to deploying SSBNs without Trident - it would be easy to get some out to the boat if they were really needed surely?
The whole point of having a Navy is that is can remain on station for long periods... which is why Ships generally deploy with stores that are suitable for the unexpected. I guess the significant part of the fleet that sailed from Gib for Op Corporate were fairly thankful that they were fully armed beforehand. Returning to the UK would have been slightly inconvenient...