Because Games workshop abandoned the Kroot Mercs army in favor of the Apocalypse Kroot Horde formation!! :(
But here is a reference sheet for all of the Kroot stats from the Merc army list.
However one thing about the Kroot is that they REALLY dont need a reference sheet :) Almost every unit has idential stat lines, WS and BS is the same across the whole army. Should be very easy to memorise.
I didnt include the Great Knarlocs or Knarloc riders.
However Rich has them correct apart from the Knarloc Riders stats. They were changed in Imperial armour 3. But the rest are fine.