Nope, they weren't bad guys it seems. MC gave them the stones in the pile because those ores aren't the ones he needed (and thus he would leave there). The trio were talking about warning MC about something if he happened to be the Phantasma Tamer in the rumors they heard, but it would be weird if they went speaking suddenly about dangerous stuff. MC would get scared and confused. And so they chose not to tell MC the info they know to avoid an awkward situation. Instead, the leader of the trio said "If it's us, we can help him if anything happens."