Diminishing Returns to Mascots?

The Chorizo was added for the 2006 season to commemorate Latino contributions to the game of baseball, as well as to acknowledge the Brewers' growing Latino fanbase.[6] It ran its first race (and the only one of the 2006 season) on Saturday, July 29 to celebrate Cerveceros Day (cervecero translates to beer-maker or maker of beer in Spanish; the Brewers also wore Cerveceros jerseys on this day). However, the Chorizo did not become a regular participant in the Sausage Race until the 2007 season because of an MLB rule stating that a team may not introduce a new mascot in the middle of a season

From Wikipedia

For those of you who don't know the Milwaukee Brewers, a Major League baseball team, feature a sausage race. I was thinking about the newest sausage the other day (El Chorizo) who was introduced last year. I wondered what kind of diminishing returns to mascots there are. It is interesting that the Brewers, Pirates and Nationals all feature racing mascots (Sausage, Pirogies, and Presidents) until El Chorizo each race had 4 mascots. At what point will the Nationals add another president or the pirates another pirogie. If they haven't added another one can we infer that the marginal cost of an additional mascot is higher than the marginal benefit.

Finally isn't it funny the baseball has a rule against introducing new mascots during the middle of the season?