I never heard anything about Lee Marvin being gay, and to be honest I dont believe it.
He was sued by Michelle Triola for "palimony", claiming that she had given up her (questionable) career as a singer to be his common law type wife. They lived together for a long time, I forget how many years, but it was a fair amount of years.
I think she got some bucks out of him for that, made the lawyer famous, and was the cause for a new word to enter the American vocabulary.
An interesting side note, that woman is now married to Dick Van Dyke. (and she is kinda chubby)
On the original subject, the Dirty Dozen was entertaining to a point, but I though pretty corny. Battleground was pretty good as war movies go, and do not forget "In Harms Way".
Patton was a great classic, one of the best about WWII.
Dago