I just took the time to go all the way through this thread and saw all your awesome work on the gardens. Very nice! They are always a work in progress, never perfect, and never finished, in my humble opinion. But that's a big part of the fun. Plant what you like where you like, and if you don't like it anymore, move it.
Roseblush, regarding your groundcover woes, I would like to suggest one of my most favorite and useful plants - I called it bigroot geranium, but the official name is geranium macrorrizum. I looked it up before responding, and it is rated for zones 3-8. This plant will grow in sun or shade and tolerates drought once established. I started using it on a steep slope under large shrubs and trees, and now I use it sort of everywhere. The only qualification it doesn't meet is that I wouldn't say you could walk on it, at least not much. There are a number of cultivars, and most flower in shades of white and pink. If you look at my multiplant posts, you will see plenty of it. I have not yet found a spot where it won't grow and look good. Look up 'Bevan's Variety' on the Missouri Botanical Garden website.
Just a thought...
One photo of it on the hillside:
Here are before and after photos of what my front yard/corner area looked like when I bought my house and what it looks like now. Improvements took place incrementally year after year. Gardening has taught me patience, when nothing else in my life would do so.
