Leonel believed that there was still more he didn't understand about Goggles' abilities, and maybe even things that Goggles himself didn't understand. That was because the parameters of background information and context that Goggles needed was quite… broad.
When Goggles had been working for him, it wasn't just information that helped him out, but rather an intimate relationship with the events in question.
For example, after Goggles bound himself to the army that Leonel led, he had been able to predict certain things about the outcome of various battles. However, Leonel had realized the more specified Goggles' target, the more accurate and clear his predictions became.
So, Leonel scaled down Goggles' "binding" from the army to just a small squadron that had carried the elites of his army, including himself, Rollan, Gertrude and others.