I believe we have three main schools of thought on Crappie (so far):
1) Conventional - don't have Crappie in small ponds (smaller than XX acres of water).
2) Treat Crappie like Forage: Manage Crappie by overloading with stunted bass (to eat lots of small Crappie).
3) Treat Crappie like Predators: Manage Crappie by overloading with small BG, GShiners, etc. (to eat virtually all of the eggs/fry when the Crappie spawn).
Have I missed any?
I think it is safe to say that examples can be found where both 2) and 3) have resulted in good Crappie fishing in ponds. I also don't think we have a definitive, textbook method(s) for managing Crappie down (yet), like the classic BG/LMB formulas.