A Rotation All Ending in a Vowel

Friend of the VORG Bill Arnold wrote to me today:

“I was doing some rooting around and I came across Bill’s Chuck’s note about the possibility of a Yankee starting rotation of pitchers whose last names all end with a vowel. I was wondering if this type of rotation has ever been accomplished before?

The Yankee pitchers are: Masahiro Tanaka, Luis Severino, CC Sabathia, Ivan Nova, Michael Pineda, and Nathan Eovaldi.”

Using Fangraphs yearly pitching stats, I determined the top five starting pitchers for each squad from 1871-2015. I then determined how many members of each squad had a last name ending in a, e, i, o or u. It turns out there have been four teams to do it: