When I went, which was perhaps 10years ago, the monkeys were numerous but they minded their own business. I guess they are still like that, and fighting among them is probably a rarity - this why the video above was newsworthy. I could walk around the ruins but frankly the ruins were not worth one's time. Phimai and several other sites would be more worth the effort and time.
However I was always on guard among the monkeys. You never know when one might come real close to snatch your bag or hat or phone just as you were taking a photo. So, I didn't feel relaxed and it wasn't a pleasant day.
That said, if you look at the video above, even as the two gangs of monkeys were confronting each other, they largely ignored the humans.