I got the smallest land at the start of the game, and when I started to get pressed for farmland I seized it from a neighbor. even though this gave me an additional 122 wildlife lands to toy with I was still getting prompted with messages for more space, which I think always made it really difficult to keep the carls happy because until that point it was 0 effort to make them feel unshakable.

Did you clear and plow some of those wildlands? You can do that in the "agriculture" tab.
Farmers need croplands, they don't care for some random stretches of pig-and-elves infested forest

there was no reason too, because you can only clear as much as you have farmers for. I had plenty of food

There is no such thing as "plenty of food", I find. And that also means that you were probably having a bunch of unemployed carls/too many carls wedged into too little farmland. If you expanded the farmland to close to your limit, and probably your pasture land as well, your carls should be happier. Also probably increase your hunters to the max your wilderness will support.