I think there's a major difference between these guys and what he considers an avatar though.
He granted them specifically an ability to utilize some kind of energy that they could mold into blast's. HE seemed to only make explosive energy spheres, whereas Psykorochi got the God Blast's. If Black Sperm was right, HE and Pyskorochi were probably getting their energy directly from God himself. Still, they retained their own thoughts, feelings, and motives, generally speaking. They were granted a power by God, but they were still just mere servants of him.
Garou on the other hand felt more like an actual representative of God and his will. Not just a mere servant, but quite literally an avatar, as he's termed. He got way more than just the ability to use energy blast's, in addition to his mind being directly influenced massively by God, though he wasn't completely under God's control obviously. Basically, Garou technically was God during that fight, but only a fraction of him.
Which is why I'm quite confident God is probably stronger than Saitama as of right now.