I ship started pullets for McMuray Hatchery. We only ship 2 birds in a box. If the birds are older, we sometimes drop down to one per box. We can strap 4 boxes together to make one package.
I know what you mean about chasing chickens in the rain. The wind took one of our 10x20 hoop coops lifted it up and over a 5 foot fence. My daughter came running in exclaiming something about a flying coop. We initially tried the screw in the ground anchors. They turned out to be a real pain...