I moving house and looking at a new setup Sonos Arc and Sub for the AV setup and a sonos amp connected to 6 celling speakers for music.

Can I use the sub with the Arc for AV then when listening to music use it with the speakers vai the amp?

I think it looks like I’d need 2 subs to do this which seems like a step backwards from current AV receiver and speaker setup when the main point in Sonos is integration, have I understood correctly?