Pasha, don't be silly! The problem is that in the rule regarding scrolls, there is a reference to TWO rules concerning magic specialists, which is where the confusion comes from.
No, you're a little off, the problem isn't that, but rather that rule 5.8, "It is forbidden to use scrolls of 4th and 5th level spells without building the corresponding level of the Mage Guild (MG) in any of your castles. If the starting castle does not have the corresponding level of MG, then you must proceed according to subparagraphs a and b of paragraph 5.2," sounds a bit wrong...
One of the correct options, in my opinion:
It is forbidden to use scrolls of 4th and 5th level spells without building the corresponding level of the Mage Guild (MG) in any of your castles, or you must proceed according to subparagraphs a and b of paragraph 5.2.
The fact that this rule refers to another rule is perfectly normal and is called an analogy of "heroic law":D