Eh, the age of the actors isn't the only anachronism. The GIs encounter some children born during the war -- one fathered by one of them -- and they're in their twenties or at most early thirties. Yet one of the GIs wears a MAGA hat and admits to having voted for Trump, so the movie isn't set in the 1990s.
The GIs are in the fifties, instead of their seventies. There's twenty years missing in everything!
It was a weird mishmash of Black history, Vietnam history, Indiana Jones, preachy polemics (Spike Lee's trademark), Black empowerment, US government mistreatment of African-American soldiers, and wildly unlikely storytelling. Lots of questionable production decisions -- one of the few GOOD decisions is that anytime somebody gets shot in the movie, a squib of blood gives good splatter.. You rarely see that.
I give it a C overall.