A few things to talk about here.

• The 5s are overkill  for surround duty, so yes, replacing them with SLs does make sense.  But The 5s can easily do surround duty, so if you don’t have another use for them, leave them as surround.
• You can only have a single pair for surrounds.  So if you got SLs for surrounds, your 5s would become their own separate room, and could no longer be played with TV audio (without an echo effect).

So, I would go ahead test this out.  Move the 5s to the X position, rerun trueplay, and configure the surrounds at the proper distance in the Sonos app.  Leave it that way for a week and see if it’s an improved for TV.  Also see if you feel like the back of the room is missing having the 5s near the closet.  If you don’t think TV audio is better, move the 5s back.  If TV is better and the back of the room is fine, leave the 5s at the Xs.  If TV is better and back of the room is lacking, move the 5s back as a separate room, and get SLs at the Xs.

FYI, I actually went through similar process, except the back of the room was my kitchen, and I had 3s, not 5s.   I did end up with Sonos Ones at the X positions and the 3s as separate room for the kitchen.  No regrets.  But your tastes and room may be different.

I really appreciate your reply.

The entire room is an open plan kitchen - living - dinning room. It’s aprox 100sqm (1000sqf)

From the left side of the sofa is the kitchen and left from the 5s is the fire 

all the left side has windows... 

I am not sure how I am going to have good sound in all that room 

I might put the Ones at “X” (having a surround when I am watching tv sitting in the sofa) and keep the 5s back for extra sound in the large room when I am listening some music 

I could put the 5s in the bedroom but… won’t be too much for a 30sqm (300sqf) room?  

Thank you