Connie Mack - intentionally left out. Racked up a million wins but also a million losses.
Mack was a great manager. His career record only looks bad because he took a huge beating when the stock market crashed and he kept the team for another 20 years after that, when he had no money to stay competetive.
Up until that happened he was pretty much the most succesful manager in history, winning nine pennants and five world championships in his first 31 years. He had two of the most legendary dynasties ever, the 1910-1914 team that won 4 pennants and 3 world chamionships with the $100,000 infield, and then the 1929-1931 team that won three straight pennants and two world championships with legendary stars Lefty Grove, jimmie Foxx, Mickey Cochrane and Al Simmons. Holding the last 19 seasons against him would be like holding the early Mets teams against Stengel.
Did you read the entire post? Mack is not like Stengel at all. Stengel managed an expansion team for four years and quit. Mack managed a team he owned, so not only could he never be fired but he was responsible for purging it of talent on multiple occasions. You mention the last 20 years but the 1915-19 A's were a far uglier sight - 3 years of sub-.300 win% and a .305 win% overall. That's the worst 5-year stretch any team has ever had and almost certainly will be that forever. And unlike Stengel he is personally and solely responsible because he traded Collins, Baker and the rest BECAUSE HE OWNED THE TEAM. Mack did a fine job in the years when he was willing to pay for talent but there's very little reason to think he's some kind of genius. He certainly doesn't belong anywhere near John McGraw, who had 4 losing seasons in 33 years (Mack had 25 out of 50) and a .586 win% (Mack's was .486%).