25 greatest general managers of all time: who?

The website below has good information to support the writers selection of the 25 greatest general managers of all time.

IN PURSUIT OF PENNANTS by Mark Armour and Dan Levitt

1. Branch Rickey: https://pursuitofpennants.wordpress.com/2015/02/13/1-branch-rickey/

3. Ed Barrow: https://pursuitofpennants.wordpress.com/2015/02/11/3-ed-barrow/?blogsub=confirming#subscribe-blog

For some reason Pat Gillick is between Rickey and Barrow.  I'd just be guessing if I tried to tell you what team(s) Pat Gillick worked for.  Be honest, do you know?  For sure?  I'd pick Barrow as number one but that may just be the Yankee fan in me and I won't try to justify that beyond, you know, all those countless (1921, 1922, 1923, 1926, 1927, 1928, 1932, 1936, 1937, 1938, 1939, 1941, 1942, 1943) (14) pennants Barrow's Yankees won and not including those he won earlier as field manager of the Red Sox.

Rickey probably gets the nod for two reasons:
- racial integration
- farm system.

Ed Barrow's plaque in Monument Park in Yankee Stadium August 2010 by Penale52 via Wikimedia Commons

I have only a general understanding of the creation of the minor league farm system but even merely reading the profiles these authors provide of Rickey and Barrow it makes me wonder why Rickey gets 100% of that credit and Barrow 0%.

What's amazing about their list of 25 is that many are names that I cannot match with certainty to particular teams or for specific accomplishments.  George Weiss is the only historical GM I know about.  Whose photo could I identify?  Rickey, Barrow, Weiss, Brian Sabean, Al Campanis, Sandy Alderson, Billy Beane, Frank Cashen, Dave Dombrowski, John Hart, Brian Cashman, Lee MacPhail, Dan Duquette, Theo Epstein.   More than I would have thought but still only 14 of 25.

I was amazed to see Brian Cashman ranked as number 21 all time.  I'd have been surprised if Cashman was ranked number 21 among the 30 active general managers.