You could start as a ranch hand, especially if you know how to ride. You can work on both a regular ranch or on a "resort ranch" that focuses on tourism. You just have to find a ranch that has around that 20ish employees.
But then it would fit all of your points. You are spending your whole day with the same group of people.
Drifting between groups will depend a bit on your exact duties but no matter what you are going to get to know everyone and work with others occasionally.
New things are constantly coming up to do. Your duties also change with the season. And even if there is "nothing" to do you will still hang out with the other farm hands.
You have that authority over you in form of the ranch manager/owner.
Pay isn't great but it might come with free lodging, then it isn't that bad.