I agree with you on all those things harry...
I'm sure all those things will have been eaten like I said earlier...I should have said animal instead of meat....remember animal includes fish birds molluscs insects....and yes nuts fruit and a few roots....
Like I said though they would need a lot of dandelion or burdock root to get anywhere near the calories from animals and there fat
Also they are seasonal....
I remember Ray mears eating them bull rush tubas....didn't he say they were horrible