Calling them complementary is quite the stretch. You've only talked about YAGNI twice, with one time throwing a "opinionated" label without any reason. I mean,

Calling them complementary is quite the stretch. You've only talked about YAGNI twice, with one time throwing a "opinionated" label without any reason. I mean, let's be honest here: "you ain't gonna need it". That's what YAGNI stands for, and represents. That's what you say to anyone who claims "but it would be far more flexible if...". It's YAGNI, no matter how much makeup you want to slap onto it.