It makes the most sense to have a way of allocating law enforcement and other emergency resources for special events in the region rather than having the host city try to go at it alone or use less well-trained rent-a-cops. You'll also get a area few firefighters who go up to work emergency medical services when NASCAR is at Talledega for the weekend. As long as staffing levels 'back home' are properly maintained, I'd see it as good & neighborly regional cooperation.
It will be reciprocated if there's a time Walton County needs that kind of external help.
Those firefighter who go to NASCAR are off duty and on vacation and are employed by NASCAR and not by their local departments.