Leonel, obviously, wouldn't neglect his brothers. But the changes that he could make to a talent of Earth already within the Seventh Dimension were minimal.
However, what he could do was greatly improve their foundations and affinities by allowing them to swallow demon pills.
His brothers had their own thoughts on things and Leonel didn't underestimate the progress they had made on their own. He no longer tried to guide them, he simply gave them resources and they used them as they deemed fit. Leonel had quite a lot of trust in them and he believed that they would give him a pleasant surprise when the time came.
He gave them all Focus Crystals which could help increase their affinities. Then he scheduled time for everyone to use the Perfection Stone.