The story presented to King David uses extreme abundance to reflect a reality of unlimited means. A rich man is described as possessing an endless, almost unimaginable number of flocks and herds. This picture of immense fortune is not merely a background detail, but serves as a direct mirror held up to the king himself.
The vast numbers of sheep and cattle symbolize the many wives David already had. He lived in a state of boundless options, possessing the power and freedom to take for himself any woman he desired [מלבי״ם].