Sam grabs the top spot all time on alot of peoples lists. Clay's book I remember was also extremely informative. BUT based on the available film footage I'm taking Tunney by a UD
I have Moyles book and am basing my opinion largely on it! Langford was always susceptible to a good jabber,and Tunney was one of the best. Plus he had a great set of wheels which also troubled Sam.
Its entirely possible .Langford was 34 when Fulton beat him the first time and had no eye problems. That doesn't mean that a good left jabber would not always be Langford's kryptonite.
Looking at his series with McVea, he seems to have struggled with McVea's jab in the early fights, but then he seems to have got adept at countering it with his right.
The other question of course is would Tunney take the fight? I can't see it myself, unless Langford was the champion, or he had gone back very far.
Langford won their last fight, but the two previous ones were draws so I see no basis for you to come to that conclusion.
I am going off Clay Moyles book here. McVea seems to have given Langford a lot of trouble with the jab in the first two fights, and after that Langford seems to have adjusted his technique, and got better results.