Police came about when there was a massive split between the obscenely wealthy and the starving masses, after feudalism broke down and the serfs flooded the cities of europe looking for any means to survive, the rich established police to protect all their wealth from the poor. If there's no split between rich and poor there should be no need for police. Most crimes have an economic basis. Even if indirectly, like people become violent due to growing up in fucked-up conditions which are due to being broke. If everybody had equal access to the wealth they produced collectively, 90% of crime would be gone like that, the other 10% (jealous lovers shooting each other, psychopaths, etc.) could be dealt with by some kind of community watch program- like every neighborhood could elect certain people who they trust and know are capable of community defense to patrol the area in shifts, basically make sure nobody's killing or raping nobody. It should go in rotations, different people taking turns doing it, so that it doesn't become one exclusive group who start getting power-hungry and acting like cops do now. Whoever does this should be accountable to their local community.

So if they were to find it necessary to set up something like that in Shashamane I would have no problem with it, but when you set up an official permanent police force with no direct accountability to their local community, you're giving people a lot of power, and the saying that power tends to corrupt is true. What if some particular faction in Shashemane started using their police to keep down other houses? Or acting like the AshkiNazis and trying to lord it over the Ethiopian-born people?

So I guess my answer is "it depends". We should beware of giving individuals too much authority over others, authority is a thing that humans tend to abuse.