Have you seen these "Shriners"? First of all, they didn't have enough to cover every door and entrance. Secondly, they average about 80 years of age. Third, the ones near where I had my season tickets wouldn't do anything other than watch the game and, occasionally, tell kids to move away from the railing. Fourth, some of what you think were "Shriners" were actually Lions Club members with green jackets to supplement the Shriners.
At some point, every school is going to have to hire professional security for their doorways. Its not perfect, in large part b/c those professionals seem to be 19 year olds, but you can't rely upon a group like the Shriners anymore. Heck, even the Reds don't have enough old guys with towels to wipe off box seats anymore.