I don't think I've ever seen this, so I'll ask: can you have two New York's (Yankee Stadium, Shea Stadium) or two Chicago's (Wrigley, U.S. Cellular) in the same league (AL or NL)?
The only times I've seen two New York's or two Chicago's co-existing in a world, they've been in different leagues (one in the AL, the other in the NL).