In my mind "complacent" means the opposite of "pro-active" - not taking actions or decisions in the face of an issue. That could be because of feeling panicked or uncertain. So I was also surprised by the "smug" and "self-satisfied" parts.
I don’t get the smug. But complacent has always has the “self-satisfied” and “a bit lazy”. Not exactly what is in your comment, but someone that is rooted in his behavior, but not for stubbornness or arrogance, just “it is ok that way because I’m happy and there’s no reason to change”
