IMO, except for primary Law enforcement Federal agencies, and the FFDO pilots, I think all other agencies with arrest powers should be stripped of it, and it all gets put under the U.S. Marshals and when they need to arrest someone, serve a warrant or whatever, they can call the Marshals and have some armed officers sent along.
There's zero reason for the IRS or Dept, of Education etc. to have armed officers who've gone through FLETC.
Some BLM goon wants to "arrest" some ATV'ers or target shooters for something, and they're long gone by the time he radios for some U.S. Marshals to come make the collar?
Boo hoo.