Well, if being an amazinhunk qualifies him, there were a LOT of better choices.
Boyington's real parents were divorced before he got to know his real father. He was convinced his step-father was his real dad, until after he was married, a father, living in Tacoma, WA., and enlisting in the Marine Corps. Knowing your father would disqualify you from M.C. service in those days, but I think Boyington had the added advantage of being part Indian (disqualifying him from other services, perhaps). Certainly, Boyington could not have made his way into the USAAF (boy, would they be sorry).
At that point he was an impromptu wrestler, but the Marines taught him to fight. From that day forward he was a real bastard. No, Conrad can't compare, but really; what actor could?
Boyington clearly lied about his AVG history, but not significantly. Comparing his total kills, though, should be open to interpretation and suspiscion.When the AVG was absorbed by the USAAF Boyington was given a dishonorable discharge by Chenault.
I still haven't worked through the B.S. to figure out precisely how he got back into action, but he certainly did not fly his P-40 (as depicted in the series). Joe Smoak (Col. Lard) was certainly a lot tougher than Boyington, so you can't really buy the series depiction of him, either.
Boyington wasn't a great orator, though a braggart. I think Bronson would have portrayed him well. Besides, they more alike than Conrad ever could.