I doubt that the US military itself is using commercial CAD software, most likely they are using something in house. Again, CAD software is not Extreme Ultra Lithography, where it is a marvel of engineering and can only be produced by one firm. The netherlands can rightly be proud of ASML as a national achievement. But CAD software? Now that's just goofy.

Check out: https://www.army.mil/article/249241/armys_powerful_open_sour...

But I would assume defense contractors -- the private firms like Lockheed -- are probably using commercial software. The US military is pretty bureaucratic and is filled with bespoke stuff, whereas the contractors are basically businesses and would use whatever is common in commercial business world.