You could use them for Latin America and the number of dictators and rebellions against them.
You could but they wouldn’t resemble much in the way of any of Latin American armies in terms of uniforms or equipment. They’d look nothing like Somoza’s National Guard, El Salvadorean or Guatemalan troops. For El Salvador and Guatemala your best bet would be selected items from the Empress or Gringo South Vietnamese. By the time you get to South America the weapons divide for the period is G3/FAL, no flack jackets and the uniforms more closely resemble the older fatigue uniform.
Paint ‘em up in ERDL and you could use the Marines as ‘70s era RRF. Intervention against Iran anyone? Stray Cats and Storm the Iranian Embassy?
There is a US Army box due out. They would be perfect for the Rangers in Grenada, who wore Vietnam era jungle fatigues and M1 pots. If you ignore the slant pockets (mostly hidden by webbing), make some small adjustments to webbing and ignore the absence of 30 round mags you could use them as early ‘80s GIs by painting them in Woodland Camo.
If they produce M-14s or you can source some, you could shave off the trouser legs and come up with reasonable proxies for the Marine invasion of the Dominican Republic in 1965. Personally I’m hoping that someone will produce some early war Marines.