In the long run, nature appears balanced. In the short run, it seldom is. Grazing populations spike, followed by a spike in predators. Nature has cycled that way for eternity if man is not present. So the core question is, do we manage nature for the maximum benefit of man? Or for some bong-induced concept like Gaia? Wolves in small, managed numbers do help the strength of herds, but when they get too numerous herds decline and the wolves turn to domesticated animals - and hunting suffers as well.
We use to notice this when we farmed. We would see rabbit populations grow substantially over two or three years and then they would decline as the fox population increased. Soon the foxes ran out of rabbits and they died or moved out and the rabbit population took off again. On one end of the cycle we were loosing crops to rabbits, on the other end we were loosing chickens to the foxes. No matter what, there never seemed to be a part of the cycle where the farmer won.