Regarding the strength of pole barns. There were many correct comments about bracing the pole shed I just built. I can't argue with the suggestions that we need to brace that building... and we will cable stay it.
However, this is the barn that we tore down at that site a year ago. It also used 6x6 (150mm) wooden posts. 80% of them were rotted off below grade and we decided to take the building down rather than repair. I went around with a chainsaw and cut most of the way thru every one of these 6x6's... I cut all diagonal bracing.... and we still had a hell of a time pushing it over.

So the elasticity of wood comes into play here. I'm starting to think that my new pole shed will wobble in the wind but it won't fall down.

Maybe Charlie303 or Sarmale can weigh in on the elasticity of wooden posts?