I think the reason for the unusual mounting height is to clear that vent underneath them, while keeping the panels together. To allow it to open.
I have 3 up top on mine, and they're not all located together. They're flex panels and are flat mounted. They seem to work well. If/when I replace them, I'll probably just leave them in place, and mount 3 new hard panels above them, unless there's some reason not to do it that way.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)