I totally agree that Ramsdale would have loved that match. I don't know if he's normally as good at catching crosses as Raya, but it seems like he enjoys the physical stuff more. And, he definitely loves a hostile atmosphere more.

Arteta really handled it badly. If he'd just said the normal thing, like "we saw a good goalkeeper available, we went for it, who's going to be the #1 will be decided on the pitch and in training". Then it wouldn't be such a big deal. But, he pretended that the two goalkeepers were going to be swapping in and out, sometimes even during a game. That led people (probably including Ramsdale) to expect that Ramsdale would get more chances. When he didn't, especially after shaky Raya performances, people started talking.

The end result is that you have Raya who looks shaky and uncomfortable, and Ramsdale who looks beaten and then tries to do too much. He had a great goalie, he bought another goalie who might be better, and the end result is two mediocre goalies who are both having issues.

It seems like selling Ramsdale at Christmas might be the best solution. It might give Raya more confidence, and let Ramsdale play while he still has a very good reputation.