I've done a couple of picket fences driving in metal posts. 2" powder coated steel driven into ground 2' with my SDS hammer drill. A 2" waffle attachment works perfect. I stand on a 6' ladder and tape 2 torpedo levels to the post while driving it in. 2" posts are correct scale for such a little fence and are invisable from the front. Self tapping screws fasten small brackets for the stringers. Way easier than digging holes and pouring concrete.
BTW, the fence boards look rotten but are not. It's pecky Cedar from a tree I dropped and let sit for year before milling to let the peck develope. The fungus stops when the boards dry out and it's actually very stout lumber