Of course it will be quite difficult for Al-Hilal to do the same thing twice so they only need to defend the title and at the same time strengthen the lines they feel are lacking. I think Al-Hilal will spend hundreds of millions of euros on two or three more players and certainly can't wait to see Neymar's real debut during the season.
And this will also encourage every club to be more enthusiastic about bringing in new European players in this transfer market. Al-hilal is quite perfect this season. But they definitely understand that other teams will strengthen their squad again next season. So it is possible that Al-hilal's strength, which looks strong this season, will not be so strong in the next season due to other clubs bringing in more quality players. Especially Al-nassr who always seems enthusiastic about hunting for players in the transfer market.
I don't think if Al Hilal needs to hire superstar players like Al Nassr, in fact, we know Al Hilal is a team with good teamwork and made of players who know each other well which means they can get better results because of their coach.
But Al Nassr still failed to win the Saudi League title even after they hired players like Ronaldo for their team, maybe they need to use a new coach to have a team like Al Nassr but considering the situation in both teams, it's not surprising to see Al Nassr starts hiring superstar player before Al Hilal.