Yankee Stadium was not built to be a football field. Taht was not what Col. Ruppert had in mind. The Giants didn’t arrive until many years later.
Prior to building Yankee Stadium, the Yankees shared the Polo Grounds with the baseball Giants. Yankee Stadium was built to take advantage of Babe Ruth.
I have been to ballgames at all three of the ballparks I mentioned. All three had deep CFs, shallow foul lines, and good power alleys. That forces you to play baseball, not Home Run Derby.
You keep saying this park had "good power alleys." Maybe you think it wasn't designed for football, but there's no getting around the fact that with the exception of the foul lines, the left field dimensions were 40-60 feet longer than the corresponding right field dimensions.
The stadium opened for the 1923 season for the Yankees. The first college football game was played there in October of 1923. College games were played there regularly over the years.
