No, you are not paying attention. The current immigration system allows some foreign nationals to serve in the military. many mess specialists and dispersing clerks are foreign nationals in the US Navy. It is very common. Very. This has been going on for about 200 hundred years. After their enlistment is up they get green cards. It has been this way well, forever. There is no need to change any law or change how that is being done. Its a red herring.
That is totally different that the prevailing conventional wisdom (among some) of “kick them all out” regardless of whether they served or not. You are suggesting there IS a path to a green card for some. A small sliver perhaps, but some.
And they are more than “mess specialists” and “dispersing clerks”. Some are in combat, and some have been killed in action.