Here's one of the outdoor Zoo setup from the side:
Here's another one:
Looks like they had 2 big stacks on the far ends. This is the only U.S. tour I missed, so don't have firsthand knowledge.
Regarding the volume on Vertigo indoor, plus some of the sound quality issues, I often wonder whether Joe's hearing is pretty well shot after 30 years of running the soundboard. I mean, wouldn't yours be? That's my theory for why Vertigo indoor was so loud and crappy sounding at times. I remember the second Boston Fleet Center show in May '05, Blinding Lights just sounded like noise from the middle of the floor. He got the sound dialed in better after that, but still, it was too loud...
In my experience, the outdoor shows are much better that way...