Enemies Accumulate has no effect on townie fights because townies do not have relationship decay towards each other, since only relationships with sims you currently are playing decay. Townies, particularly Hobby Mavens, fight because unlike regular townies, Hobby Mavens do not have any preexisting friendships with each other, and thus their relationships are pretty much entirely decided by initial encounter, which is guided by "Lot Tone".
Hold on. That's the first time I've seen the phrase "Lot Tone", and seems to be the only use of the phrase (in relation to the Sims) on MATY or anywhere else. I understand what it means, but what are the technical details? What governs Lot Tone? Does placing specific Maxis items on a lot determine what kind of autonomous townie interactions occur? Or is it just something general, like Environment score, or is it randomly determined?
I *have* noticed that I tend to get autonomous fighting between townies or uncontrolled playables on community lots that aren't dance clubs or restaurants, but haven't seen any other pattern. If I had to guess, I'd say that if an object with strong advertisement is on the lot, it sets the lot tone, but if there are only low-advertising objects that meet the same needs, autonomous social interactions will dominate, and those frequently produce negative relationships between autonomous strangers. Is that correct?