I was E-4 for about 4, I'd have to look.
But, nukes could make E-5 by reenlisting.
So, if they needed 1,000 E-5s, and 990 reenlisted, they'd only promote 10 from the tests.
And, nukes take the promotion test on radar and comms. Not nuke stuff.
That's my excuse, and I'm sticking to it.
We had a guy doing his driver training on a tracked ammo carrier that we used to haul an electronics hut on turn the dam thing onto its side. Wish i had the pictures still.