People don't realize that part of diverging from our monkey ancestry traded a lot of brute strength for dexterity. Chimpanzee's can weigh as much as an average adult male, but their hand and arm strength is enough to literally tear your face off.

Not joking, there was a lady who made the news because a chimp removed her hands and then all of her facial features. The way muscles insert in their arms and the upper arm/forearm proportions maximize force but reduce the range of motion and fine motor control, but it's still like fighting a middle schooler with the strength of a couple of adult men. And also that kid's a an angry cannibal.

Apparently chimps have been seen killing and eating gorillas. Basically, monkeys can be rough, but chimps are scary as fuck. This website almost reads like it's joking, but all the numbers actually line up and it seems like a legitimate zoology website.