Griffin's books do tend to be fairly similarly themed, so despite ranging from OSS in Argentina during WW2, OSS anywhere else in the world (Men at War series), The Corps, Brotherhood series, and the cop series...... you see the same type characters and themes pop up.
One reason why he keeps selling books, familiar topics, places, times and people. He's a good writer, but for a "Details man" (well known about knowing every little thing about the subject) he does get some modern stuff wrong. There is no CAR-4 (CAR-15 or M4, not both) the Air Force has not had Air Commandos in decades, etc.
Still, a good read. His knowledge of the WW2 era is very good, which is why the Honor series does very well.
He did make some mistakes. One of the worse I remember was where the Berets were in the Congo fighting the Rebels and one of the guys was using a 1903-A4 Sniper rifle with a scope but loaded it with stripper clips.