I would lay money on the types of service with the highest casualty rates (eg junior infantry officer, combat pilot, special forces) being even more heavily overrepresented by atheists. I derive this belief from the educational and intelligence requirements for such posts, and the correlation between educational attainment and atheism.
I further add that I bet the majority of Freepers who post this "no atheists in foxholes", and "atheists won't fight for their country" bullshit have never themselves been within 1000 miles of any combat.
I'm not taking that bet....