Some quick notes for you.
Squadron is an Air Force term, equivalent to a Battalion in Army/Marine terminology. A company sized element is called a "Flight", and I don't know how they break down beyond that. If those are Soldiers, that would have been a Platoon, seeing as it was led by a Lieutenant.
Berets would have been an anachronism in the 1950s, worn as unofficial headgear by tanker units I'm WW1 and then Army Rangers in WW2, typically modeled after the beret of choice worn by the British units they fought and trained alongside.
Sergeants stripes point upwards on all US Army uniforms from WW2 and onward.
Just some constructive criticism. As an Italian living in Britain, I wouldn't expect you to have indepth knowledge of American military. I get more upset when I see big companies like Marvel or DC put someone into a Staff Sergeant's uniform and rank, and then call them Lieutenant.
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Heed these words: I do not draw. Photos if you're lucky.