SPL's built on Chinese ideas they've had for their football leagues. Some euro players went to China but their league wasn't good so it's failed. SPL isn't like them they're trying to be competitive. They've made the SPL famous because they want to host the football world cup.
To be honest the difference is made by some clubs in the Saudi Pro League investing a lot of money, meaning they have bought many European Player so we think it's because of them that this league is more popular than China's. The steps they have taken in football in an increasingly dramatic way really surprise us because they are now willing to pay a lot of money to keep a player like Ronaldo. At the moment, it seems that the Asian super club is building on their success at the moment as they have brought good performances through many Latin American players in the Club World Cup.
Yes, i agree with you that the huge difference that makes them separate from each other is the only money. One of the main reasons for the popularity of the Saudi pro league is they have the players they don't need any introduction in all over the world. A player who is heavy on all the football squad Cristiano Ronaldo is the part of the Saudi pro league and many other players like him. Saudi Arab is playing on the next level now by signing the most famous and the most talented players they are just enhancing their popularity and their views. So they can host a football world cup. Cristiano Ronaldo is highly paid in Al-Nassr without having any well known trophy or title the main reason his stay that management don't want to let him go. His only stay is favourable for them.