I was talking about this only this morning. We came to the conclusion that you if you are spraying at a fair rate of knots you will have to dash behind just as fast.
So one spraying another ruling off behind. Then one guy going like the clappers dashing while some mug of a labourer has to keep putting the catch sheets and trays down, keep filling the buckets up, taking sheets and trays up and keeping the machine topped up with powder. So a 4 man gang at least.
I would like to think that it could work though.