Checks, Balances, Defray Responsibility Not Risk

 When something goes wrong, you can blame the balance or the check, rather than having to blame yourself. "If only you had let me--"

  Imagine a slave. Imagine someone owns the right arm, and someone else owns the left arm. Yes, they now have to work together. Only in very naive theory does this make their interests align. Mainly it makes the slave useless. Maybe they violate the balancing system, by making it fake or by buying a second slave to go around it. Maybe they just get their slave stolen. Conquest. Either way ownership will return to its natural whole.

 What if - and I know this is a real cloudy-headed fantasy - you work together with someone who keeps their word. Does things when they say they're going to do it, and doesn't do things when they won't say they're going to do it. Then you align interests using contracts, without unnaturally trying to split wholes down the middle. 

 With a balance/check system, it's a way to farm blame for incompetence. "We can't make a slave soldier, the guy who owns the left arm can't use a shield." All his fault, see. Naturally, revenge is sour. An effective society, one not run by eunuchs bureaucrats, can't develop a [balanced] system in the first place. The incompetence and paralysis comes first, the system appears to justify or excuse what's already happening.