RE: Sunlight
My experience with shady roadways - is that clovers, rye, etc will grow - but that tonnage is greatly reduced. Maybe helps to proved a "walking snack" to a doe an her fawns - but probably doesn't support them all for the year. Its really tough to compare shaded woodland plots with field plots as far as what can be accomplished - but definitely they can serve apurpose - I always plant a few.
FH