In the case of many, though not all, black slave owners, that “ownership” had less to do with labor than simply being a freedman husband buying his wife, or parents, or kids, etc, in an effort to reunite family or friends. This would explain the disproportionate statistics.
Wish I had some stats on that.
I would have to see the stats on your assertion, however could we not also assert that some white families bought slaves in order to free them? and to unite families?
That makes sense