Have the first lot of solution for both machines already made up hot in the truck from home so they dump it in as soon as they have lifted the machine out and they are running.
I assume you have already been onsite, I almost always get a copy of their floor plan. This not only enables me to estimate but also allows me to scribble notes regarding cleaning, stains, heavy walkways etc. I then sit down briefly with my guys before going in, and plan the best approach.
Get them into the cleanest areas first. That will then allow the third tech to review the heavily soiled areas and plan it effectively and pre spot etc.
Nominate a lead tech that can see the bigger picture. This will be essential in anticipating bottle necks, planned breaks, quality control, running water and solution to the machines to keep them running, shift furniture ahead and behind them etc. in my case, I try and always be the third tech. I have the ability to oversee a huge job and anticipate the above and plan effectively. I will releive the other guys, but not for great lengths. If one of your guys is better at this than you, nominate them for that role.
The lead tech/third guy should be the busiest of them all.
I don't have two cimex's, rather a Cimex and a 21" Brute so I also plan the effectiveness and strengths of each machine into my planning.
John