I'm going to play devil's advocate here: _what if_ most of lower level engineers are actually not able to self-organize themselves like this dedicated, I bet hand-picked group of PE can? I'm pretty sure AWS ruthless culture would gladly use less middle-managers and be swifter in time to market if it were so easy, no? What works for a single, highly-focused project (or a handful of similar situations) doesn't scale when you have to take care of bazillion customers, do boring/smaller tasks and keep the machine ticking.