Mmmm the only common is both of them use a ton of money to buy european top players who are old or with not so much space in europe, but Saudi go one step further and start to own players who were already in top condition, plus Saudi football is way advanced than chinesse one, you can see it on the National team, and one last thing is they are more closer to europe in travel distance and, a lot of players who are muslims wants to go there because of religion.
You may have a point when you bring religion into this, but checking statistically, how many muslim players have left the European football to join the Saudi pro league? This is something of question before concluding that most Muslim players go there because of their religion. The Saudi pro league is now far better than the Chinese league which was once a place most top footballers play in before retiring from football.
The Saudi pro league pays better and has achieved a better rating now than it use to be when compared to the Chinese league. The Saudi pro league will soon become a place where not just old players that already made name will want to play in but where all players will love to have a blueprint also with the way they’re going about football. We have seen young players wanting there too now, more will go when they’re not given the chance to showcase their best in Europe with the teams they’re playing for.