I'm with those who say, different kids/groups of kids may need different approaches. What works with one child may not be so effective with another. And in the same, one provider may be able to easily do guidance one way another provider may be better suited to guide the children in another way, maybe closer to how she was raised. If we're all turning out kind, obedient, confident children I don't see the problem.
And if I was having the amount of issues the OP is having then you'd better believe I'd be listening to every single post on here looking for anything to help whether it's in the books as DAP or not! If I were you, OP, as another member already stated, I'd terminate the worst offenders and work with the rest. Once the group is back under control you can refill those slots. Oh and one book that I really like is "Kid Cooperation" by Elizabeth Pantley. I checked it out from the library, and only read the first few chapters, but it was enough inspiration and advice to rein my own 2 wild children back in.
Good luck, OP!