Leon thought of giving that knowledge to his friends via Telepathy. He could trust them. However, even if he could, his enemies could still use skills like Mind Reading to obtain that kind of knowledge.
Regardless, Leon used Telepathy for something else, to them for the humans he could trust, and then Leon would give them the power of the spirits first. However, even his friends could trust them. Leon would have to access their memories in order to confirm that they weren't spies from the harvesters. Leon also passed that message to Hector, Amanda, and Maya.
"Well, I guess this is it…" Leon said and prepared to leave. "If you guys need train some recruits, I can send some monsters here. Although they will be summoned monsters, you guys can still obtain coins from defeating them."
"Yes… that will help a lot," Gisela frowned. "We are counting on you."