Death Adder Hatchling, Moon Moon and Rage Peep, breed does not matter.
use poison fang until you can hit, blinding poison, poison fang and puncture wound snake dies breaker kills adder with headbutt, bring in Moon Moon do Moon Tears, Howl and Moon Fang twice Breaker dies Moon Fang on Frog until last move and howl Moon Moon dies, bring in Rage Peep Peck twice maybe 3 times and frog is dead. No RNG easy fight.
I also had to use the 3rd pet; my Warpstalker Runt was only able to get in one attack against Stickers before dying. I used a B/B Vale Marmot and B/B Warpstalker Runt. I'd randomly picked a P/S Arctic Fox Kit (2-1-1) for my third pet. Crouch, Leap, Flurry, then Leap till Stickers died.
Hmm... What pets and breeds were you using? And where did the strat fail? You are correct that there is some RNG with how many times Scales Lash ability hits. I tried another 3 times. 1st try didn't even need 3rd pet. 2nd & 3rd attempts Vale Marmot died earlier, but was able to finish off w/ 3rd pet. Lurking Owl Kitten (if you have him) makes good 3rd against Stickers.