266 in my current desert game. They eat Unifallow steak, and feed themselves with a little help. It works better with the debuffs from raw meat disabled, the large eating time is already a big penalty. I have over 300 Unifallow farms, and a few fences to stop them straying too far. It was more than i needed, but better to err on the safe side, i thought.
I often seemed to have to manually order a lot of butchering to keep the food supplies up, it seemed that the automatic butchering only happened with close unifallow, of which there aren't many for long. I need someone to herd the far ones into town.
When i didn't get a 16th hero, i first went from 256 to 266 in case of some sort of wierd error, then started a mountain game for more space to build bedrooms.
400 in my current mountains game. The second floor has 16 dormitories of 25 personal rooms. They eat omlette, and are having no trouble feeding themselves. Still only 15 heroes. I have less than 50 chicken farms, and it's possibly a lot more than i needed, not that
it matters. There's a fair bit of afk while waiting for the peasants to turn up.
In either case it runs very smoothly so long as i don't leave much on the ground, except when wall building.