This may be an older thread but.
When we washed back home on weekend's we went out with 2 machine's running and 3 brushers. Soap we used was zep t-n-t. We use it from fleet washes to house gutters and Norfolk southern rail machines to heavy equipment. the stuff is OK to 2 step in some cases. Never needed to worry if it dried, if it did just rewet so the brusher can do his thing. On a hot day black trailers can start to dry before your done soaping it. I cant understand how you guys can use a soap that will cause damage if it dried wile watching out for overspray and keeping it off chrome before it dried. Ive only cleaned fleets one way so I don't really know.
On a average Saturday we had 2 guys go out and clean 3 vans at a couple hotels in the city, 3 others go clean 4 steel haulers, we then met up and did about 30- 45 beer semi's and trailers. If we met at the same time 2 guys would start to pull out every other semi wile 3 guys prepped the brushes, hoses and sorted key's . We then had 3 brushes go 2 on one side of the box, one guy did the cab. and the brushers would go to the other side. front row, back row, front row back row. The 2 guys on the wands 1 would wash the back row wile the other did the front. After this we all went out and did around 50+ school buses and vans in the same method. So 5 guy's 2 machines we did around 130 pieces on a Saturday from 7am to 4pm at 4 locations/setups. Sure this may be overkill to some but quality was great, every new customer was impressed with it. Coming it after they hired the "franchise mobile guys" who showed up by himeself and left with zebra stripes, soot and dirty wheels on everything, they understood " you get what you pay for" and were ok to pay a premium.