I have confirmed recruitment in one of my two 1/4 acre ponds. There is no cover except a load of rocks on one end, and a couple of aging brush piles. However, the pond is very muddy, which may help with survival of fry from Bluegill, and the occasional small LMB. I have not stocked any CC since about 2020, yet at least a few 8 to 10 inch ones are coming to feed.
I have been told that recruitment in small ponds is rare.