When I first bought my homestead there was a lot of overgrown and sickly looking trees which were tangled up with tons of grape vines. It took a long time to clear it out which left me with a 15 foot high pile of woody stuff to deal with. I chipped some but not everything fit easily into my small chipper so I had a lot of kinked branches that just ended up in the
compost pile. Even though all the wood wasn't completely broken down by gardening time, I added it to my raised beds so that It could continue breaking down in the soil. This was long before I made it to Permies and learned what H-Kulture was all about. I must say that having those pieces in the beds has made all the difference in the moisture levels of the soil. While I'm not sure it would be hugelkulture, it's something close and it's working. Those beds get water very rarely and seem to do just fine. I guess the lesson is: Adding woody stuff to your soil improves water retention no matter how big or how small. The more, the better, of course but there's no set limit (high or low) so far as I can tell. The more you add, the longer it lasts.