The problem is that when Apocalypse finally hits, it only kills the frontline pets (your opponent's and yours unless you move your roach back to the front ), so unless your Hatchlings brought down his other two pets, the match will still go on. On the plus side, with two Hatchlings there is the distinct possibility that you will have killed off his other two pets.
As for it being a stall team, I would call just about any comp running with a Sunflower and Ancient on the same team a staller
. I guess that the argument could be made that you are going for a kill every 15 rounds, so it wouldn't be made simply to frustrate and cause flees. Still, most of the comps that I run could kill one or both of the healers before the countdown if they are left out to soak rounds till apocalypse ends, which would leave you with one healer and a fairly sub-standard pet at best after the spell hits. Still, can be fun to try. I did something similar with two SS rabbits and a roach, but didn't have very good results tbh.