While the wishbone era qbs had some great W/L records, they were playing on very good teams that relied on powerful running attacks and strong defense. I'm not saying that there wasn't talent there, but it would be very difficult to get a meaningful comparison between Tery Davis, who rarely passed and had an at best average arm, but excelled at making the right read in the wishbone, and Barker, for example, who was a very efficient passer in his junior and senior years. I wouldn't consider them for comparison purposes (or Pat Trammel for that matter, who was a very tough runner who again rarely threw the ball. The 59-61 teams won on kicking and great defense.)
Namath, Sloan and Stabler all played on strong teams, but they had that mystique about them. You almost knew for sure that if we needed a late drive for a win that those guys were going to find a way to get the team down the field. While Shula didn't have the arm strength of those three, he did have the field and huddle presnece as a starter and also led some memorable winning drives. Barker was an interesting case. He was a game manager in his first two years as a starter, but Homer Smith made him into a very effective qb gis last two seasons.
I regard MacElroy differently. Maybe it his just me, but he does not project the strong on the field personality as the others on my list. Perhaps it is the difference in back then and now, since so much was called on the field then, and most everything is called from the pressbox or sidelines now. He is very intelligent, very efficient at what he does, I will grant, and certainly played well enough a year ago to get us the crystal football.