“..., what rationale was used to pile them up outside the palace fence, and not to heave them right over the fence onto the front lawn....”
Because piling them up IN FRONT of the fence is Peaceful Protest.
Heaving them OVER the fence is an attack and an act of violence. Especially to nervous LEOs who are already in ready-to-go mode.
Actions, like words, mean things.
You’re giving me too many ideas here. Remember the guy in Montana a few years ago who took out most of a town with an up-armored bulldozer? The dozer could just as well have been remote controlled. And that WhiteHut fence is not a contest to anything with a little horsepower. But I like the gallows set-up just outside the fence just as much to make the point that the Kenyan needs to mind his manners and knock off the Mussolini krap.