I seems to me if we're trying to move moisture from ground level to the top of a hugel pile it would be better to orient the wood vertically instead of horizontally.
The natural pathways in the wood that move water up and down the tree should work in a similar manner while wicking ground water to the top of the pile.
My average length is about 5 ft. Easy to lay down, difficult to stack on end. Should be fine for short wood. A small mound could be built first, then long material leaned against it in near vertical position.
There is a saw mill near me. I should suggest that they stand the logs up, to save space. 😂
My excavator built piles probably contain some vertical chunks.
I plan on building some vertically oriented hugel mounds this spring to test this theory out against my conventional horizontally constructed mounds. It won't be for another couple seasons before we know for sure, but the logic seems sound and worth experimenting with. I plant on using the post hole auger on the tractor to make a kind of barricade style spine (sinking poles three or four feet deep and about the same out of the ground) then building up soil and wood on either side until I get them covered and ready to plant.