Open fault ticket with Sonos and was closed with no response after my replies.... Poor form from support ticket [ ref:_00D1N2JMtd._5002KfxieJ:ref ]
Best answer by Ken_Griffiths
In Google's case, you can only assign Routines to Google devices, as I've attempted to show in the screenshot attached.
This is 'perhaps' on the Sonos “to do” list, but Sonos never, or rarely, announce their development roadmap, so it’s anyone’s guess as to when, or if, we will see this feature.