Add to your worrisome situations the fact that there was an attack on the base as Panetta landed. Turned out to be a lone suicide bomber, but there was no way to know at the time he wasn’t part of a larger effort. And knowing that, we disarm our Marines.
I would think a decent CO would simply order a Pass in Review, have the ranks then assemble in formation, Port Arms, Present Arms, to check their bolts, then order Parade Rest or At Ease, for the speech. They would still be ready to act while a perimeter security could be roving in parallel. Simple grunt tactics every Platoon Sergeant grasps.