It always drops one plate so gettin less than 1 should be impossible. I finished the plates portion for ochain. it was me and a mule and sometimes a friend. In my first 10 kills in grauberg i was told the altep guy drops two more often so i went there. I was thf pretty much every kill, except a couple to see if my ninja killed it faster. I did NOT get 2 until my 15th kill or so, so i went back to the easier grauberg iGiant. after about 30 plates of almost all 1 plate droppers i said fuckit and i went ninja just to speed up the process. i think in total i had 5-7 kills drop 2 plates.

I am not complaining of course, i can just confirm that they seem to drop 1 more often than 2 plates. At least compared to most empy item droppers the 1 to 2 ratio was a bit lower. For other empy's i went ninja + mule just for the all but one red proccing ability and faster kills, cause the 2 item drops rate wasn't really that bad.