From Sonos:

While you can’t activate Sonos Voice Control and the Google Assistant on the same speaker, you can activate the Google Assistant on a different speaker in the same system.

That’s what I was hoping to do. Just didn’t know if it was possible. Thanks. 

It’s possible, but the One needs to be in a different room in the app. It can’t be a One surround with the Arc.

This is part of the ‘Google’ rules. They’re the ones who say you can’t have two voice command systems on a single device.