[gnaritas]

Of course it weaker, but tons of two chord songs only have I and IV, it's a sound well burned into our ears. Anyone studying music theory would not be surprised by this. Perhaps I'm meaning something different by classically trained, I just mean trained in theory, not the classical period in history.

I also dislike this idea of breaking the rules, theory is descriptive of music, not prescriptive. There isn't anything you can do that can't be described by theory, that's its purpose. The rules aren't rules, they're just common idioms that people use, using an uncommon idiom is not breaking a rule. Rule is not a proper word to use.