phweeew.... I finally managed to defeat all three guardians in one playthrough, much thanks to your hints here. And now I have some questions.
1. I defeated all except Babooshka. Can she be beaten? I've seen her in two forms, not quite sure what that means. I don't know if there is life after Babooshka.
2. After I beat the 3 Guardians I immediately tried again and failed, due to the random nature of daily profits. Is there more than one way or strategy to beat them, or is it always the same path? i could have easily tried my exact method several runthroughs in a row without having succeeded.