Did...did you forfeit a fight after 169 rounds this weekend?
You can try the 1 lvl 25 + 2 lvl 1's. Better hope you dont run into any AoE teams, that would be my concern.
The double Sunflower + Magical Crawdad team is strong enough to get you through. If you're the person I fought, I would recommend using Solar Beam when you get to full health (2200ish). Sunlight > Photosynthesis > Solar Beam > stun > stun > Photosynthesis > Swap. Only a Howlbomb would kill you. If you see a Howlbomb coming, swap in your crabby and time Wish to go off the same round as the bomb. For more attacking power, try a Fiendish Imp or Ore Eater. The Imp's Immolation will heal it on the backline and Nether Gate is great for removing pesky pets. Ore Eater's Shell Shield is a practically a 3-round bubble, plus Acidic Bite will give him some heals on the backline.
Honestly, this achievement is as much about luck as skill. I got mine when someone instafled 3 times in a row after I beat him in the first match then my fifth match was against a team I matched up very well against; dragons dont do well against Ore Eaters.
The problem is, fights are (usually) very fast with lots of damage. Graves pumps out over 1300 dmg total (750 via BONESTORM, 668 via Grave Destruction) in two rounds, MPD is 592 every three rounds (Thunderbolt), Darkness teams prevent healing and drop massive dmg quickly. Avoidance only goes so far.
A couple teams to try:
Done Did Kid (from Discodoggy): Ghastly Kid, Fiendish Imp, H/S Scalded Basilisk Hatchling (breed is crucial). Idea here is, goat Haunts, basilisk stuns, hits, the Feign Deaths, Imp Nether Gates pet to backline, Immolation, swap to goat, rinse, repeat. 1000 unavoidable dmg without taking much if any dmg (goat may take a hit in the first round). Not great against critters or pets with >305 speed, but still effective. Many run away once they realize what's happening and their slow pets will be perpetually stunned and dotted to death.
Blind team: Umbrafen Spore, Seaborne Spore, and...shoot, cant remember, been a long time since I faced it. Essentially, this team is a stall team. Keep rotating fast pets that can blind, but do 0 dmg. Stall long enough and the opponent will give up.
Good luck!