Because the trojans didn't have a strong abstinence message.
The Blue Devils.
It goes from Trojans-Blue Devils-Tigers-Wombats-Hornets, so in the end they are the Merryweather Hornets, yet in the movie this is different.
I believe there is Duke Blue Devils in Durham NC and Depaul Blue Demons in Chicago.
the answer corrolates with the "soul" of the institution
"Blue" for the VFW color and "Devils" after Concord's local landmark, Mt. Diablo).
Merryweather wears blue, Flora wears pink/red, and Fauna wears green.
Mount Morris School are the blue devils too
Trojans blue devils tigers wombats hornets
The blue jays mascot is Ace.
Hamburg Blue Devils was created in 1992.
The mascot for Duke University is the Blue Devil.
In the book "Speak" by Laurie Halse Anderson, the school mascots are the Trojans. The main character, Melinda, refers to them as the "Merryweather Marthas" due to their overly enthusiastic school spirit.