"In fact a fair number of buglies are considered special treats and are not all that different from eating shrims, crawdads, calmari and the like."
Different enough.
"White Oak acorns are sweet..."
Not that sweet.
And only if you cook them, which is hard to do if you're really in a survival situation. Lighting a fire without matches is hard hard hard. Freeze-to-death-before-you-succeed hard.
"Generally gatherers spend less time on survival than farmers"
And less time on Earth too.
Soaking acorns is no biggie.
A lot depends on where a person or group ends up in the survival situation and how much history they have there. The situation for gatherer societies is one of having lived there for millennia. They know the food water and shelter resources.
Oh, and making fire is only hard if you don't know the correct woods and techniques to use. There are websites nowadays for that, but back then there were the older folk.