There are few institutions more like the U.S. Army than the National Football League.
Uniforms and helmets and training camps. Stick with your squads. If you're on time, you're late. Be 15 minutes early. Pull up your socks or you'll pay. Next month's optional workouts are mandatory. Take ground. Never retreat. You're injured? Next man up. This is war.
Above all, in both, you do what your leaders say, no questions asked. They bark, you bolt. If you think, you hurt the team.