We just get it dropped off at the site in a huge pile - sometimes separated by size. We pay a lot per hour of delivery service. That's why we tell them to drop it.
Irrespective of delivery charges and cusomary drop off procedures, one can pick up illegals who will do whatever you tell them to do for $25 plus food and a ride.
I see your problem. The key to this is have the delivery schedule laided out with your supplier in that curtain materials are delevered on time, when you need them and not before, in one big pile. But you need a supplier who gives a damn to do this right.
But if you do it that way, you can save yourself a weeks worth of labor on a small house. As long as your workforce does not slack off, nor there is bad weather.