It's not really a comparable situation. Saruman de jure held Isengard in fief to the Steward of Gondor, though he had long since made the surrounding area, Nan Curunír, de facto an independent jurisdiction. His attack on Rohan was a straightforward invasion of a foreign country. He was in no sense a landlord: he had no legal authority over Rohan, or even a pretence thereof.
There's no real similarity to the enclosure of the commons or the highland clearances in Scotland, either, which were measures imposed by the nobility on the peasantry of their own country.
A reminder that fiefdom can be complicated. Henry III was at one time Duke of Aquitaine (in fief to the king of France), Lord of Ireland (in fief to the Pope), and King of England (in his own right, answering to nobody). Saruman was an emissary of the Valar, and that was his primary role, but in his position at Isengard he was acting as a lieutenant of the Steward of Gondor.