All you've done to reduce the effort is to provide gearing in the form of leverage. You end up doing the same amount of work, but it takes proportionately longer. Work is force times distance moved. A lever allows you to apply a much bigger force, but it moves the stone a proportionately smaller distance, so the work is the same.

You make the work easier so you need fewer men than dragging, but they are much slower so you need more teams working in parallel to achieve the same work rate. If you applied these additional men to dragging, the dragging would be much easier.

As an illustration, consider using a block and tackle to drag the stones. You could have 20 pulleys to reduce the effort so that one man could provide the pulling force of 20 men, but the progress would only be 1/20, so you would need 20 such systems in parallel to get the same throughput as 20 men dragging one stone. So why not just drag the stone with 20 men in the first place?

I also don't believe that you can reduce the friction to 6% without using rollers or copious quantities of lubricant and with only 6% friction, dragging would be a doddle. If you can achieve such low friction, I'll give you a race dragging with the same workforce over the same surface for the same distance.