I would agree that there is a certain unfairness about having different-sized divisions, for the reasons you stated.  However, both the AL and NL have to have a even number of teams for scheduling purposes.  If things were evened out and both leagues had 15 - 3 divisions of 5 - then either there would have to be an interleague game every day, instead of at certain periods of the year, or one team in each league would have to be idle for a day or more likely 3 days at a stretch - the equivalent of scheduling a series against a null team.\n\nThe only ways to fix it would be to either go back to the old divisional set up - two 8-team divisions in the NL and two 7-team divisions in the AL, or expand the AL by two teams, so that both leagues have 16, and go to four 4-team divisions.