There should be no such thing as volunteering for a massive, profit making, enterprise. Especially when the events you are volunteering for are directly their revenue generating business.
The cheerleaders can be fired, required to show up at specific events and take specific training, for a profit generating event for a for-profit company, that is not what I think of when I think of a volunteer. Also, I am sure the Bills organization makes money directly selling their likeness on calendars, postcards, etc.
I say give them minimum wage and workers comp, or get rid of them.