@Aohige_AP:
I don't think the generations really have anything to do with it.
Quite simply, the whole "three magi" rule is per world.
Since we have at least two separate worlds in the mythos, that means we can have up to six magi total existing at the same time - three from Alma Toran, and three from the current world.
At the point Solomon made Aladdin a magi, I presume at least one of the three magi had died in the war of Alma Toran.
The generations refer to comments about Gyokuen being the "fifth" magi.
Given Alma Toran's destruction, everyone except Al-Thamen is pretty much dead - except Solomon's household which now lives on as Djinns.
There could be six magi in total, but I think the story works well with five (or four when Scheherazade dies). Magi are pretty overpowered so there shouldn't be that many of them.
Also, since all the djinn are basically of Aladdin's former household, does that mean he's now, by definition, the strongest character considering every djinn is a servant of his? The Djinn choose kings, the magi guide kings, but what happens when a magi is a king as well? He's the king of kings really. Going back to what I was saying a few months back, could Aladdin now create his own djinns as well?
Although there is still some confusion in the mythos, this arc is pretty damn good. I can't wait till Mor and Yunan show up!