I'm not totally sure, but my best logical guess is that ground anything would be easier b/c the body has to to less work - freshly ground that is, and soaked in acidic medium, etc. Actually sprouted grains (maybe also spr.legumes) are probably the easiet of all to digest... I've heard their composition changes so much that they're as easy to digest as vegetables.
Re. grain vs. legume, I think this might be an individual thing for each person's body... a friend of mine has very sensitive digestion and she can't eat beans at all b/c they make her bloat (even soaked) but I'm fine with beans. Then there are the people who are gluten intolorant so most grains don't work for them.
Hope you get a definitive answer from one of these really knowledgeable mamas