ace 52 and acwr are both very high vertical recoil weapons... to not get headshots means they would be microbursting their shots with the first shot being in the knees and the 3 /4 being in the upper Ace 52, 1st shot in the chest 2nd one is in the head. The muzzle break doesn't do much to calm that down anymore.
G36 has almost no vertical recoil but pretty high side to side. IMO the G36 would be most likely to have a high accuracy out of the carbines with a low hskr. High being 22 -25 %