i am using this exactly, everyone and everything is maxed, and i am stalled at stage 145.
Wow it takes a lot of fishing to get a good enemy arrangement but it can be done.
Least amount of bats as possible (preferably only one) -> Enemies are as grouped as possible, with the bat somewhere near the middle -> Poison the bat first, then get everyone poisoned -> Hope it works out, but if not, resume fishing