My personal opinion: You will do better with a fleet of ZTR mowers.
Here's my thinking. 6-7 foot ztr mowers are common. With sharp blades you can move at a speed of acres per hour. (2-5 depending on whose lies you believe.) The big issue with the wing mower is the loading/unloading time, and the price of the unit. The ZTR's can be loaded in a minute, if you have a trailer set up with chocks. And I bet that 2 of htem would be cheaper. You will have to pay for twice as many operators, but you can teach a high school kid how to run a ZTR in about 15 minutes.
Unless it's a big complex, a soccer field is under an acre. If you have a machine that does 2 acres per hour, then the basic mowing is half an hour. Meanwhile, you still need to deal with the edges.
Gang mowers are for golf courses, road side allowances, and BIG parks. (10s to 100's of acres)
Go find someone else who has one and follow them around for a day.