You can do this, but you will probably experience a slight audio delay from the One SLs when playing TV audio that will result in an echo. Streaming music will be in sync though.

FYI… the Arc already includes the center, front left, and front right channels. So adding the One SLs up front isn’t necessary.

Thanks a lot. Actually I don’t know what to do with the one SL as I’m not sure whether Sonos have any exchange policy

Move them to another room and use them as a stereo pair or put them in two different rooms. Or sell them or give them away.

Don’t forget to take advantage of the Sonos Upgrade Program.