The idea of "Defend the Valley", as it pertains to Avon, was thought up by 90s & 2000 DC/HC, Jon Acton. It was a play on Psalms 23.
The Valley is an attitude... "Yeah, though we walk through the Valley, we shall fear no evil, for we are the baddest hombres in the Valley!"
You can see it at the beginning of the MASTERPIECE that is the 1995 Avon Football Highlight Film. Featuring cutting edge graphics, wicked soundtrack, and a young #34 that now leads the Human Performance Program for the Crimson Tide. Enjoy!
https://youtu.be/uQRmjlArQww?si=FXGhDEPptLFiXW05
Not trying to dispute the current head coach's explanation of its significance to his team. Merely explaining the origin.