I'm surprised to see you quoting Earl Weaver since you tend to refute other people's points with hard facts. I get that he knows the game and there's wisdom there but it's hardly quantifiable. I figured you'd be looking at actual metrics vs speculation from someone who last managed in the majors in 1986. The game has changed drastically since then due to analytics.
I have conceded a few times that I agree with your basic premise that a manager does not add much in the win total. Talent wins. But Weaver was probably the pioneer when it came to using statistics. He would sit Boog Powell against Mickey Lolich because he had gawd awful numbers. But Ausmus would still run him out there. That is where the differences lie. Just like there is a difference between losing because the other team is better and losing because you make too many mistakes or just mentally incompetent to make sound baseball decisions.
Ausmus DOES NOT play the better player. The Tigers lead all of baseball in Blown Quality Starts, by a lot. Which means he has no clue when to pull his starter. Since becoming the manager, DET relievers come into the game the least amount when the game is tied. And when they do come in, hardly do they enter at the top of the inning when ahead. All of this will stress even the best bull pen. The team continues to make bad baserunning mistakes. On and On I could go as to the bad baseball that the Tigers exhibit (with statistics for demonstration). This is the reflection of their manager, because he is making most of these decisions or he is not addressing the bad decisions by the players.
If I am Justin Wilson, there are big differences when I come into the game with the bases load and no outs, a man on first and one out and entering the game at the top of the inning. I might get out of the first time I am put into the high stressful role, but not day in and day out. If every time I pitch it is from the set (stretch), the stress adds up.
DET Inherited Runners Scored
2014 = 32.8 IS% (14th in AL, 28.7 was average)
2015 = 32.1 IS% (12th in AL, 30.1 was average)
2016 = 39.7 IS% (14th in AL, 28.9 is average)
Last 2 years
J. Wilson 18.3 IS%
M. Lowe 19.6 IS%
A. Alburquerque 31.1%
A. Wilson 42.9%
This year
A. Wilson 50.0 IS%
J. Wilson 50.0 IS%
M. Lowe 40.0 IS%
Clearly, DET brought in relievers who had success at stranding base runners and they immediately conform to the DET standard. Why? You could argue the pitching coach, but he isn't the one bringing them in the game, day after day, in high stress situations.