We arent at that part yet, but Isla also isnt at the stage yet where he is "20mil value" or "equal to licht" by any means.
As it stands, Licht is the definite starter, and Isla is fighting Padoin for the first sup role.
Next season, if Isla makes or breaks, we could actually have this discuttion.
It would take quite the offer from madrid to sell Licht IMO.