Used a drawing program (TouchDraw for iPad) to analyze the differences in tarp coverage. The hammock in the pics has an 8' structural ridge line. The tarps are 10' and 12' long hexes and diamonds.
With both types you have to hang the longer tarps higher to clear the hammock suspension. With the hex you still get a good bit more coverage from the 12' long version despite it being higher. Interestingly even the 12' diamond still leaves you fairly exposed.
Of course real world experience is better than drawings but hopefully the comparison is still useful.