There's safety and comfort in being just a cog in someone else's big hospital, and not having to make any clinic-wide decisions, and having rules set for you.

Isn't that exactly what *didn't* work about the last (allegedly) permanent job? That they set rules that you didn't manage to immediately adapt to? Whereas this is a situation where the rules would be much looser, and set by someone that you already know that you can work with productively. Sounds worth trying to me.