There are castle strongholds, control of choke points, a lower strata that are required to work the land and pay tithe upwards to the military heirarchy.
Feudal systems have existed in times and locations where there was little need for military defense against external forces, they persist in form as a polite, polished, chivalrous bikie club on horses, mafia with great houses.
Warrior nobility systems farm farmers.
A farm is a system with many living beings, but most of the benefits accrue to those we call the farmers.
A farmer farm is a called a fief (feudum in latin), so it's no surprise that under feudalism most of the benefits accrue to those who have control over heaps of feuda.
Would it be true that under capitalism most of the benefits accrue to those who have control over heaps of capital?
[to the original point: capitalism works very well when it allows people to trade and specialise in their comparative advantages; under what conditions might it work less well?]
EDIT:
> little need for military defense against external forces
I think they were also successful even where there was need, as long as those external forces were also based on a warrior class.
What Napoleon managed was to "scale" the nature of warfare; two poorly remembered quotes from a book one of his cavalry generals wrote:
— 10 mamluks could beat 30 french, but 100 to 100 was even, and 300 french could beat 1000 mamluks
— our troopers' horsemanship was pitiful, and their officers' not much better, yet with this cavalry we made the tour of Europe
I'd say both point to innovation in the use of mass over class.
It motivates a search for the mystical beast: Marxist financier (not the pastry?)
(Not to mention elucidates the boney/HF-inspired principle of intertwining* (wrt scaling — CENDEC, decentralizing by centralizing — marxist-financing-in-itself))
Note that 1984's Inner Party, despite not owning anything, benefits from everything; compare Plato's Guardians: https://news.ycombinator.com/item?id=24069572 (or Номенклатура?)
On a straight CenFi note, even Cicero is more subtle than he'd appear by my contextless quote in https://news.ycombinator.com/item?id=41796726 ; he may have enlisted Cato to frown upon usury, but I take http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%... as implying that he smiles upon clipping coupons: Sed ut pecuniae non quaerendae solum ratio est, verum etiam collocandae, quae perpetuos sumptus suppeditet...
[the distinction between ownership and benefit in both code and common law jurisdictions has its roots in roman law, but unless either of you are really interested I'm not going to delve in that graveyard]
EDIT: HF? Our Ford?
EDIT2: for an SAP advertorial, I like TLTF! pigs acorns etc.