I would be in favor of making some military service, O or E, a requirement to be Commander in Chief.
It just makes sense to me that if someone is going to be in charge of the world's most powerful military, they should at least know what it's like to be a part of that military. Just my .02
If this is your reasoning, then why shouldn't they also be required to have service as National Park Service rangers...and TSA...and every other large arm of the government?