Personally I wouldn’t put a pocket. For many reasons and one of them being what you listed. Other is dirt and junk. And a big lip for vehicles. A good slope is all that is needed. But that takes a bit of effort in finishing. Not much though.
I like to see the skirt boards above the floor level. Treated lumber is much more tolerant of weedeaters and mower decks bumping it than siding, and it also doesn't look as bad with dirt or gravel dust splashed on it.
