'It depends' on your goals. They are good at surviving, some consider them as being bad or 'invasive'. They are a cash crop in the south for human consumption. If your goal is to have lots of crayfish then you are all set.

There is some concern about the effects of 'burrowing' but I have not researched this or had personal experience. It matters less in groundwater ponds vs ponds that have a dam.

IF they have no place to hide (rocks, rip rap,) and you have predators that can fit them in their mouths the population control will reach a 'balance' If they have lots of places to hide then a few stocked will turn into a mountain of crayfish which again can be a good or bad thing.

Good if you want to feed large predators or want to harvest for crawfish boils, bad if they overtake the pond and eat every aquatic plant and eventually keep the bottom stirred up lowering visibility and fertility of your pond.

I'm sure others from the south can speak to this. However we don't really want to analyze it to much as I doubt you can get them back in those gunny sacks and back to the grocery store.