Just closely have read rules for Sheep and Hills and discovered that hills can be used for fields too!
Did you know about it right from the start and how often you use hills to steal a field?
Yes, this was the basis of our first big question mark on the expansion. We had a battle for a nice size farm and one player argued that he had more followers on hills so had a stronger presence. I could not argue against it. HiG has seemingly, though somewhat offhandedly, answered that question - but we still play that hills are cumulative toward majority. But, yes, we knew it from the start.