You could set up workers like settlers. Have 2 males, 1 female, and then a child worker in each group. That would look pretty cool I bet. Of course this simply represents the building of the improvement and not the working of the plot.
I don't think it would work properly because the animations for the worker are made for one or two workers (i.e they move across before they start building a road). If there were four workers it might not look right, but interesting idea..