Well to be fair you have already suggested that has greater validity by virtue of being included in the "series proper". Which is a reasonable point, though I don't believe it is conclusive.
On the other hand, while, as M'Sharak points out, "Kirk as a stack of books on legs" is not, as far a I know, supported by anything we actually see, neither I believe is it contradicted. Not even by a movie that was billed as a prequel!