hives in location can vary a lot, I can put 400 on a location but would have to feed all the time, to get honey certain location can't handle more than 5-10 hives, I have some yards with 20 hives and some with just 7 hives, some location just can't support extra hives, not enough to forage on. since it can be like this here I put about 10 on a new location and keep checking to see how much they have coming in, if a lot then I can put a few more but if not much then I take a few from that location, I just try to keep enough hive at a location to maximize the flows. to many hives in a single location can eat up all the honey so its best to not over load a area unless you know it can handle it.
I spoke with Leon Metz, a former commercial guy in SW WI at our Spring regional meeting. His response to the same question was about the same as TwT's above. He told me his limit was 10-14 spaced about two miles apart, until he saw the results. I know he made money, and had to quit because of health issues. Location, Location, Location. Not the almond groves up here.