textbooks are completely wrong about 止まる

Textbooks make 止まる look way harder than it is. Actually, it literally only applies to things with legs stopping. A person? Yes. A dog? Yes. But a clock? No. If a machine stops, you have to use 制約 or just say it's dead. Actually, maybe a car can 止まる if it's parked, but definitely not a watch. Stop overcomplicating it guys, it's just about legs.