About synergy?

None of the approaches you list are sufficient alone to assure good results.

Its all about the synergy and how each piece interacts as part of the whole to deliver the final results. Infinite ways to accomplish this. Never simple, unless you happen to get lucky. That's just the way it is if you are one that must achieve a particular sound.

Being smart about it and doing the homework needed to understand what you are doing is the one required element regardless of what final mix of stuff you end up with.

There are some design best practices that can be applied to help deliver optimal results faster, but that is a topic for another thread perhaps.

I'll go out on a limb and say that any real improvement to quality of power should always result in positive improvements in sound quality, so it is one tweak that is more about optimizing performance in general and less about synergy. If an improvement in quality of power produces negative results, then I would look elsewhere for another aspect of the system that is not up to snuff perhaps. Synergy may come more back into play at that point.