You're probably thinking 'damn, what a waste! Why not condense more spiritual cores using that same amount and rise through the levels quickly?' which was a valid thought, but also not really.
The reason why Master Elandor was enthusiastic about Dante was not because he could condense more cores with his "naturally" higher intelligence, but because he could condense bigger cores.
This would mean that at every stage, Dante was far stronger than his peers, which alluded to the whole 'foundation' thing popular in those eastern fantasy stuff. However, just like in those eastern fantasy novels, such a thing required more effort and especially more resources to go further.