In any healthy small community everyone tries to, in order to keep a good reputation. In case of misunderstanding any third party appreciated by both parties may act as a judge/referee. The need for a government, especially central, only arises when the group isn't anymore a community but a large set of (on average) loosely related and interacting persons.
> Two people working together is pretty much politics. It's government. It leads there. Cooperation requires coordination
Coordination nor politics doesn't imply any government.
And then when you start having insane judges who rule that raping a child is perfectly fine, you will want to stop it, and thus you will invent your standardized laws.
There IMHO is major differences between "a single government, dedicated to regulate" (which attracts people willing to control others, often letting the most unscrupulous gain power) and "any chosen third party".
Where most people are most of the time reasonable they will oppose insanity, if necessary forcefully.
Second, it doesn't really matter. Two people working together is pretty much politics. It's government. It leads there. Cooperation requires coordination.