Wagtail
Horse servant
Why do you seem to think you would need 3 acres per horse for them to just live at grass??We keep ours at grass and don't have 3 acres each and they winter just fine. Even without rugs.
Of course you can keep a horse on less, but they need supplementary feeding and your land will get trashed (if it's clay like ours). I know from experience. Dear me, I get attacked for having my horses on an acre of land and now for suggesting that ideally horses need three acres. What a shower!