Garrick is accurate, or maybe a robot controlled by GPS, but lasers and robots are just not cost effective (lasers themselves may be worth a try, but robots with lasers....not so much).
We don't have a "Gigantic" quick pitch, but when we setup the Klassic, historically we have ran kite string from point A and B, spray with chalk a pattern of 5m 2m 5m 2m... down the kite string, then use 2 quick pitches at each 5m spot (the 2m are the lanes)with 3 people to setup pitches. 15 seconds a pitch is what we have done in the past. The 2 quick-pitch use allows all the pitches to be aligned AND rectangular vs. parallelogram.
Once upon a time, we used tape on the quickpitch, and after "production" work in the hot sun, we found the tape would slide a little. Now we use a new system for marking that includes shrink-tube so that doesn't slide anymore.
There are other more 'geometric' ways of doing it but as you swag a few mm's here or there it amplifies as you continue down the row. It's possible after 16 iterations you are now 3.2cm off kilter. I'm not mathy enough to do this, but Chris Hodges and Eric Anderson have done it using math and geometry. For me, I suck at that, so I rely on the Quickpitch systems.
Or, someone could fund this idea: