Did many JTF’s while Active Duty with the BP. We had only one person with ammo in each team (unless we were where we weren’t supposed to be and were never there so I am not saying anything about that because we weren’t there). Also didn’t have live ammo on our deployment because the RoE did not allow for that.
It all comes down to the monkeys in DC that make up the rules….. Any time you have a group of weapons, however, one person wlil have live ammo to protect the .gov property. That is about it most of the time, unless it is considered a combat zone.
Maybe some of it has to do with Posse Comitatus? Not sure if our government really cares about stuff like that anymore.