You are completely right ...
Synergy matter first and last for sure...
Nobody will build an acoustic room around non synergetical components...
It takes to much time to do acoustic without first owning a relatively well done synergy...
Synergy is so basic that it appear evidently even in a non controlled room , and even when the other faqctors electrical and mechanical had been adressed...
But it is so evident i mention almost never synergy when i spoke about the three main embeddings controls : acoustical,electrical and mechanical...We must own a system BEFORE optimizing it ...Then we ask for a minimal synergy and embeddings controls optimization begin after that ...
evon when they spec compatibly, some components sound better together than others.
some components that sound great together are just ok otherwise. ive heard beautiful sounds from entry level rega components working together. the same entry level rega components are so-so individally. not sure what to make of it, but i sure heard it. i believe thats synergy.
i have 2 systems, and theyre both a mix. the pieces work together some awys much better than others.