A friend of mine recently purchased some sheep at an auction, but the next morning he couldn't remember how many he'd bought. Every time he starts counting them he falls asleep..............I think your brother would be better off buying pigs
If he didn't know when he bought the farm how many sheep it would support he's going to lose a bomb if he tries DIY farming. Is there a local farmer in need of some keep? Perhaps he should knock on the doors of the neighbouring farmhouses and see if they know of somebody in the region who would pay to graze their sheep on his land. Make boundary maintenance part of the deal. Whatever he does this year he'll probably better next year but you always pay for experience.