[Link: support.sonos.com]

S1 and S2 systems are independent, but can coexist on the same network. Operationally it is not much fun to have both in the same house because players cannot be Grouped, but I suppose that it might be a workable scheme to keep kids and parents separated.

In your system, since there is an Arc and you’ll need to Group rooms, S2 is the only choice. You may need to trade the CONNECT:AMP if it is too old.