For Arsenal it's a good choice because they lack such quality and Rodrygo would upgrade their team and probably aid them to win the EPL title but it's a big lose for Real Madrid. We'll from what I've observed in the FIFA Club World Cup, Xabi Alonso haven't given Rodrygo more playing time so it could mean that Rodrygo is not welcomed in his squad and needs to leave. I might not be right but the rumours of Rodrygo leaving is getting intense so there's this slight believe I've got that he'll leave
After Al Nassr committed €500 million to Ronaldo, he also made it a condition that the club bring in strong signings. It seems Ronaldo is now trying to bring Rodrygo to Al Nassr. Hopefully they sign him, because I think if Rodrygo joins Arsenal, he may disrupt the team chemistry. Apparently, Real Madrid is asking €90 million for him. Arsenal shouldn't be paying that kind of money anyway. One thing is clear, Rodrygo's Real Madrid career is over. He will definitely be transferring to another club in this window.
Perhaps Rodrygo doesn't fit in Xabi Alonso's pattern and this is common to happen to player(s) when a new coach comes into a club. Rodrygo just 24 is to me too young to take his career to the Saudi Pro league, and I agree, Arsenal won't be a favourable place for him even if Arsenal can afford his fees. Where I will love to see him play is PSG or Bayern Munich.