Jumbo,
I didn't know that you were referring to modern actors.

I'm not going to parse words with you regarding "effete" or what have you. I'll use "hetero" in quotes, if that's better. I believe that you're saying Americans see the British (in film) as delicate and efeminate.
(That must be why they call it The British Disease)
"Effete" literally means "worn out." I don't know if that's what you really mean to convey.

I'm talking about these actors as they appeared as soldiers.
David Niven was very good in Dawn Patrol.
There was nothing "effete" or whatever about Michael Redgrave in Battle of Britain.
Michael York was a soldier in several films. What about Zeppelin? Alec Guiness in Bridge on the River Kwai? These guys were great.
Of course, Clint Eastwood, Bronson, or Mitchum could kick them all out of town. But... they're... Americans... you know?