We can create events or statuses that "cause the claim to be true", and create predecessor/successor between these events. I guess that this could be done using an interface for capturing data, which would be as simple as the current one for qualifier, but which would handle the more complex structure behind the scene.
Trying to be clearer on the position I expressed before: I have no doubt that any solution to this problem will look like qualifiers, from a pattern perspective. What I'm really puzzled is the use of the exact same technical solution for presenting (1) qualifiers that describe the claim itself and (2) relations that pertain to what is described in the claim.
The French wikipedia page says that Abdallah II was preceded by Ahmad, in his role of sultan. The wikipedia page does not say that the claim "Abdallah was sultan" was preceded by Ahmad.
But actually looking again at the wikipedia page another solution for answering the challenge comes to mind. It becomes more simpler if one considers the dynasty that is indicated in the table:https://fr.wikipedia.org/wiki/Dynastie_Alaouite
Just consider that this dynasty is an ordered list, in which Abdallah II appears 6 times. This is what the data should be. you may still indeed have something that look like qualifiers on the Wikidata page, but it would be just a matter of apparences, as it would just be interface sugar (either to enter the data or display it) on top of that ordered dynasty list.