Obeying a chain of command does not mean you have to be dumb. As a matter of fact, it is every person's job in the military to report unlawful orders and not follow orders blindly.

Additionally, the entire command structure in most American branches is setup for each unit to operate somewhat independently. As an example, a general or admiral says: "I want those 10sq miles flattened by tomorrow and here is all the equipment it should take to do it." Every division, unit or whatever, figures out how to do it. If they have problems, they can reassess the situation on the ground and report back up that a strategy is or is not working. Units on the ground can coordinate with other units to ensure a smooth attack.

In Russia, the chain of command doesn't work like that. The generals will tell units what to do, and that is that: One unit attack from the east, the other from the west and hopefully they don't start shooting at each other.

(I over-simplified a ton, but you get the idea.)

Also, the military absolutely wants you if you are too smart. The problem is, those smart people can get 20x the pay with half the shit in the private sector.

When I was in the Navy, two of my five years were spent in school learning electronics, radios and computers. (I slept through IT school since I could have probably taught the classes anyway.)