Work is seasonal -
It is in the tree section near the bottom, it costs approx 150 Ranch Cash each.
Deposit more Pokemon
The jobs these men carried out were seasonal. They would be needed for doing a certain job at one ranch, and when they have completed this job, the ranch no longer needs these men, so they move on.
First, on another account, bid 0 on the horse you want. Then go to the account that has the horse you want on it an accept the bid. Ta-da!