How many patients can one doctor take care of per year? How many people can one farmer feed a year?

Was just thinking that there should be doctor clubs, where a bunch of people pool their money to hire a dedicated general physician. Or to have a shared tailor, or group cafeteria, or whatever.

The ratio of people covered to specialists would probably determine whether it's feasible. You'd want the specialist to still get paid a healthy (and guaranteed) salary and to have a more satisfying relationship with customers. And the members of the club to get better service / product than they would otherwise with middlemen taking a cut.