That's a pretty normal reaction. After all that schooling, it's a bit of a culture shock to get thrown into the real thing. When I went through, the academics were loosely related to a reactor design that is no longer in use, but was still used then. The prototype they sent me through in Saratoga was a plant that was only used once, and was obsolete before I could walk. Then I went to the fleet and had to learn a brand spanky new one that neither of them taught me.
Tell him to look at the bright side. If he had stayed in Charleston for prototype, he'd be training on an obsolete plant too. At least the one that is still in Saratoga actually exists somewhere in the fleet.
It'll all click soon enough. It sort of hits you all at once. The best thing he can do is to learn the systems by walking them down and putting his hands on whatever he can. If he tries to understand them by memorizing the drawings from the book, it will be harder.