Al Nassr have weakness in defense, but they will have to face with a bigger issue of the whole league. It's barrier for the league development in future seasons after three latest seasons with super star and star players from Europe and mass money spent. I read a report recently that appearances of Cristiano Ronaldo, Karim Benzema, Mane, Neymar, Brozovic, and more star players from Europe latest years, are not enough to increase total spectators in each match in Saudi Professional League.
The Saudi Professional League and investment from PIF and attention from Saudi Arabia government will have to reconsider their developmental strategy for the league, and their national team. So far, spending mass money seems to not work too well as expected, it's kind of buring money quickly while impacts on young players and national team are not too good and uncertain in future.
I have to be agreed with your all view about this league but still you also need to understand few ground realties Saudi League is just had new start with huge investments and big stars from the world because they are on verge of change their domestic situation which is completely sports less.
While their main object to bring big names was to have good intention from the world media which achieve secondly their object was to host FIFA World Cup which is also achieved, but now they are in most difficult road which is bringing competitiveness and stability in league which is not easy. Here they needed time and strong infrastructure they are having enough sources and their strategy is also good even many are not agreed with this, but surely time consumed so it could be good in near future when sports culture will attract local peoples, and they will enjoy good games in stadiums.