Ensuring high quality sources where needed, especially science/academic topics (narrow focus)
I am not sure whether my experience would help but anyway. In Russian Wikipedia we had persistent conflicts between Armenian and Azeri editors. To the point that they could start fighting in just any article. At some point, we got a serious arbitration request half a year ago (I was then an Arbitration Committee member and had to deal with this case - we only serve 6 months, not 2 years as in en.wp). What we introduced in the end was to create a mediation committee whose members are acceptable to both sides and who have the last word. If any editor is unhappy with any edit in an article related in some way to Armenia or Azerbaijan, he/she files a case which the mediators decide on. Additionally, we indicated what sources are automatically recognized as authoritative and which need to be decided by the mediators, and also we prohibited edit warring: not more than one edit per user per article per 24 hours. The system is in place for about 5 months, and we feel it much easier, we did not have any major issues since, though initially, of course, some users had to be blocked.