When we talk about a defense line, the goalkeeper and the defensive midfielders are included the same the same thing applies to when we talk about attacking line wherever the attacking midfielders, wingers and strikers are included. Al Nassr's problem in the last two seasons is nothing more than their poor performance of their defense line and that has cost them a lot during these times. From your analysis, it obvious the club manager already have taken notice of the weakness of his team and would therefore work on it with the best available players at his disposal. Personally I would want to see Al Nassr challenging for the biggest trophies this season.
If Al Nassr's defensive line players have above average local players' abilities, they should be reliable to keep the sector solid and safe from the threat of goals. Well, if I review Al Nassr's defenders last season, they were less solid and disciplined. Especially Alex Telles, his performance was not stable and consistent enough. The pivot's role is also very crucial, because before the opposing team attacks, Al Nassr's two pivots must guard and ward off every attack made by the opposing team. Well, as you said, actually last season alone, Al Nassr's defensive line performance was messy. Because in the previous season, they only conceded 18 goals in one season. This season, in the two matches they played, they only conceded two goals. But at least, statistically, the Al Nassr squad performed quite well. Only a few defenders declined slightly, that was in the second week of the match. IMO, if Al Nassr insists on winning the trophy this season. Luis Casto needs to review his system and strategy again. moreover, Al Nassr players have better individual skills than other teams. well, once again Luis Casto must prepare his team to keep playing solid and consistent. especially, when they play against some strong teams in this competition. I personally will not speculate on the team that will be the champion this season, although it seems that Al Hilal has the potential to defend the League title.