Hi Rich and thanks for your ground cover question. In researching your Sarcococca, it seems like a little trimming might be all that is needed to rejuvenate your plants. I also like your idea of applying compost, although you probably won't need the fertilizer if you do. I'm attaching a website which says to prune next spring, after it flowers, to somewhere between one and two feet high. With such an established, fragrant, somewhat heat and frost tolerant plant, keeping it seems like a great idea. It might like a little water if we have a dry summer again... at least every couple of weeks.

As to the sunny spots which Sweetbox doesn't actually like as much, I would figure out what you would like to see there: flowers, ground cover, shrubs or even vegetables? Then check with your favorite nursery to see what they have and what they recommend for a sunny spot. What fun to get to find new plants for your yard!

https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=f519