Fighting is good for your community. It means that members care what other members think of them. You’re doing a good job. Seriously. If members are fighting you’ve created a close community.
You should be more concerned if members don’t fight. If members easily walk away from provocation, or retort with “i don’t care about your opinion”. These are the moments to be worried. Step in and ask “why don’t you care about her opinion?” – get to the bottom of it.
Remember why most people leave communities. Few leave a community because they get into a fight, most leave a community because it’s gotten boring.
I wouldn’t just let fights happen, I’d actively provoke a few. I’d draw attention to areas of disagreement. I’d highlight the major debates and give a “heated” rating for each. 9 means, woah…it’s getting personal in there. I’d chronicle the history of fights between members and give an opinion of who won. The stakes are high.
Bad grudges are part of the concept of a community. Fierce open disagreements help forge the principles of a community. It counters the sheep mentality, it opens the door for individuals to each stand up for their own beliefs within the community.
If it gets personal, you can step in. Otherwise, let fights flourish.