I think I can't accept the way in pairing Yamaha AVR with Pioneer speakers, or vise versa. Or Denon amp with Onkyo speakers? It will look like mixed up setup and not friendly.

Yamaha Onkyo Denon Marantz and Pioneer are not brands specialized for speakers. Therefore it should be used for their own amplifiers only. Sony amp should not borrow Onkyo speakers.. Onkyo amp should not borrow Denon speakers.

Different story for speaker specialized brands like KEF, JBL, Mission etc, they can be matched with any Amp you have.. my opinion only