Sonos and Arcam grouping

I have access to play music through my Arcam / Speakers OR my Sonos wifi set up in a second room. Roon will not let me group them together to play the same tracks through both rooms. Anyone figure this one out?

Roon allows grouping by “like” protocols. Sonos to Sonos. RAAT to RAAT. Airplay to Airplay. Etc.

You need to find a common protocol between the two which might be Airplay in your case. Otherwise you cannot group.