I know to distrupt ranks you need to have a full second rank of 5. But can you get the +1 flank and +2 rear bonus from small groups of skinks running in.
you can get +4 to combat res from that scenario. +1 for flank and +2 for rear as you said, but also +1 for charging.
Well if the unit you flanked only had 4 ranks and only one attack a piece, they they would only be able to kill 4 at best.
I agree the CR by the skinks is rough. I attacked 8 dryads with 10 saurus, fought to a draw. Then put 6 skinks in the rear and 6 in the flank. He turned his Dryads onto the skinks and even with the +4 CR it was a draw. Although they did distract anymore saurus kills.