Thank you for the insight and critiques. I value opinions and suggestions.
With that said, I believe a case can made be for a 23-year old who has seen at, a minimum, 7 years of military combat experience, assuming he enlisted at the age of 16. I believe 7 years can be enough seasoning to make a man formidable at his profession, given circumstances and being in the "prime of life."
I justify the young age with the character traits because I believe a man that were, say, 33, would not be so pious and fervent in his beliefs. More years in the military would naturally lend itself toward a more jaded, cynical, hardened character archetype, which I am not going for.
Furthermore, the assertion that age is a limiting factor in one's fighting expertise is, more a less, wrong. History is full of examples displaying young men (and "young" is a relative term to us soft modern-world people) who showed formidable skill in combat in spite of their age.
Flavius Julius Crispus, the son of Constantine the Great, assumed command of entire legions at the age of 19 and personally lead daring expeditions. Born in 305 and dead by 326, age was not a limiting factor on this man's ability to fight bravely or skillfully.
The great Hannibal Barca assumed command of the Carthaginian army at the age of 26.
Scipio Africanus was merely 17 when he lead the charge to rescue his father at the Battle of Ticinus (218 B.C.), and 24 when he assumed command and personally lead the army of Hispana.
Alexander the Great was merely 19 when he began his conquest of much of the known world, and personally lead cavalry charges at the age of 20. His age did not impede his ability to 1) fight formidably or 2) use tactics.
Am I saying my character is one of these men? No. What I am saying is that these traits are unique and not out of the realm of possibility. Above the average soldier? Yes.
For what it is worth, I removed the "skilled tactician" from the profile strengths.