You're saying Milroe at 297 yards with five touchdowns and three interceptions last year is on par with 2177/15/6 from Ewers? Any given metric, including Rivals Ranking, future draft projection, and on-field performance has Quinn a much better prospect than Milroe. I don't see the difference between should and does, unless you're just saying that anything can happen. Statistically, he's an advantage.
I get it that on any given Saturday anything can happen, but you can bet that if Saban could switch QBs with Texas he'd do it in a New York minute.