I tried to look up one of the ‘reenactment’ sites and got a virus.
I know somebody has to play the Robber in “Cops & Robbers” (or Redcoats, or Confederates, or Klingons, or whatever), but I agree that this seems to be a failure of judgment.
The disturbing aspect is that this group named itself after the bad guys. These were not guys who mostly dressed as GIs and then the guys who lost the coin toss put on the German uniforms for today’s reenactment. This group existed to reenact the actions of a specific SS unit.