I usually run it with 10 workers on flax, and the other 5 on whatever I need, like mining if I need some coal, trees if I want some bird nests etc. The 1250 flax/day alone covers the expences even if you don't spin it, and if you do spin it, that yields about 165k profit a day with today's prices. Just make sure to have 750k or more in and keep popularity at 100% so they work at maximum effieciency :