The only problem is how long saudi can only rely with the money to help the club gets demand by recruiting european players? we have seen that many times that if this is not fully worked. You can see that some players have been trying to exodus back again to the european competition.
This is also destroying the reputation of the league as well as there would be some bad reviews about this, i think that this can become the consequence when you were hiring people caused by money. They were not willing to play in this league but they came due to the money.
So, we can take this as the main evaluation to consider whether it was successful or not.
This problem is indeed quite complex and the enthusiasm that existed previously when joining a Saudi league team has reached a saturation point for several European players. Indeed, from the climate to the environment, it will have a full impact on making everyone feel at home and on the other hand, if they cannot adapt well then they will choose to leave. So far only Henderson has chosen to leave the Saudi league and I think if there is no more room for European players to come in next season then this league will also be quiet again.
However, I believe that the invested funds have not yet been exhausted and the Saudi league can still achieve several targets for European players that they have not been able to realize this season. Players come because the money is tempting, it is normal and conversely, if they come for that, it is better to be prepared for the risks involved. I think the indifferent attitude that sometimes appears from European players can be a serious problem and especially here the league itself will be affected badly.