This reminds me of a job posting I saw recently, also with a local government.

The top two requirements were:

*degree in X

*specialization in A, B, C or D

Now, a degree in X would probably give you some exposure to A, B, C or D, but A, B, C or D are also subjects you could get a whole degree in on their own. So if they want A, B, C or D, why not just ask for that?

Or, do they want someone who got a degree in X and then for some reason worked in A, B, C or D afterwards? Some people may have done that, but not many, so they are limiting their options. In any case there probably isn't anyone who has an X degree and worked in ALL of A, B, C or D. X plus ONE of A, B, C or D is as close as they'll get.

I kept track and sure enough, they re-posted the ad a second time a couple months later. I'm pretty sure they got some applications that were solidly in the ballpark of what they were asking for. My guess is the HR gatekeepers, who know nothing about X, A, B, C or D, didn't realize they were in the ballpark and rejected them.