Yes,,,,no,,,,maybe so,,,,,certainly. "Well drained" mean's different conditions to different people. Most plants in our yard prefer well drained but cacti and most succulents demand arid or near arid conditions. Advantages of hügelkultur are best realized when growing perennials (esp trees,vines and shrubs) and deep rooted annuals that require consistant moisture that is never dry nor saturated in root zone. A new mound/bed is usually topped with 6"-12" garden soil mixed with a generous amount of compost. Cover crops and/or hardy annuals are planted first couple of years to alow woody material starting decay. A similar strategy called Keyhole Gardening combine's hugflkultur with raised bed pratices to produce eatable gardens where conditions are hot and dry with limited water supply. Over recent years,I've increasingly used hugel and keyhole,having good results with both.

over time the structure of the soil will become good. I had to dig up fruit trees that had been girdled, and I could see good structure already after 10-11 months. and I did not do a real hugelkultur, it was just logs, no twigs and no leaves. don't overthink it, just bury wood and consider the bed done and fertile from now on.

I, too, am doing a hugelkultur this spring. Here's an article I wrote about my technique.

Hugelkultur: An Amazing Permaculture Gardening Technique