If someone can sell the idea better than I could, more power to you. The M9 and 2-3 mags is almost a joke, I agree.
TTPs, proficiency, and SERE tactics are issues, as well. Obviously, this is not the place to detail them.
In the end, it comes down to money. I wish I had a better argument for the higher ups to fork out money for guns, ammo, and training. The desired specs put out by the Strike Eagle guys were not met by anything currently sitting in the inventory in quantity. The GAU-5 is a half-answer for what they wanted, but big AF doesn't care about anything under 20mm...so...