Raamdale has been one Arteta's guaranteed starters to this point, but if he signs Raya then he'll have a fight on his hands because Raya is very good and also well suited to the style of football we try to play.
I think Ramsdale is the better goalkeeper, and will go onto become one of the very best goalkeepers around as soon as next season, but having two quality, hand-picked options vying for the position is what elite clubs should do.
It's also a good opportunity to take advantage of with Raya only having 12 months left on his contract, and Nottingham Forest perhaps being willing to offer us decent money for Turner. I can't imagine Raya would ask for crazy money, he's a good age, could become a top class keeper, years of PL experience, and we could perhaps get him for a net £15-20m. It's a no brainer.
I'm sure Arteta would do the same at right wing with Saka if a similar opportunity was there.