Fives are generally considered overkill as surround speakers. Additionally, the line in on any speaker set up as a surround is turned off. I’d recommend Ones as surrounds, and at least one Five to serve as your line in, as well as an extra speaker. 

Thank you for that how would I integrate a single 5 into the room with arc sub & ones as rears can 2 be introduced as left & right fronts I thought the arc acted as these, alternatively is it a lot of bother to just remove arc from room setup on app when playing music ?

You’d just set up the Five as another ‘room’ in the Sonos system, and group them as you desire. 

Yes, it’s a lot of bother to bond and unbond surround speakers. Not hard, mind you, but after two or three times, it becomes a pain. Plus, when you do so, you lose any TruePlay you may have done to the room.

If you read the FAQ on the line in, you’ll see that you get the option on where to play the signal, so it could easily be sent to the Arc’s room, instead of the Five’s room. 

5’s are considered overkill by people who don’t want to spend the money.  If you care about music set rear 5’s to full and prepare to be amazed.  it does also make a difference for surround.  Plus you can move the 5’s further back from your listening position than the Ones.  Check out the Peter Pee video on You Tube as 5’s as rears.