I don’t think their could be anarchists society with keeping inequality. So I do agree we could not solves issue link to wealth inequality. But those inequality have to solve first. This is a common point view among libertarian communists, anarcho-communist and anarcho-syndicalists.

Ofr the inter-communities issues, the whole thing is to create common interests :

• if a place have more funds, the production have to be split. To make this solution acceptable, the work needed could be equally distributed among thoses communities. The idea is to prevent wealth accumulation, create link among communities, and make the live more comfortable for everyone. Other solutions may be used, like cultural one to gather people from many places (physical activities, free party, …)
• Some working places need people from different places to be run. Like hospital, university, or power plant. This common need may prevent those agressions, but otherwise, if one community refuse mediation, some non vital production may be stopped. Like electricity, radio, or other cultural stuff

Again, their is no common recipe. This stuff have to be experiment from now to get more and more efficient.