Multiroom with Russound *and* Alexa/Echo

Hi all,
I finally managed to integrate my multi-zone Russound (CAV6.6), which I use for “dumb” 8-Ohm ceiling speakers. Now the family wants “Alexas” in their rooms to use the better sound instead of the echos.

Is there another way, to achieve a (wired) multi-source, multi-room solution with Alexa than what I scribbled here (pardon my drawing… :smile:):

red: speaker cable
blue: cinch cable (Russound input)