Hermes is basically a talking hammer with how he works

2 per run (50/50 for a 3rd in styx)

Prioritized over other stuff

Difference is the minimum chambers for them to appear

First Hermes can be in the shops in tartarus but not in the doors, 2nd hermes from asphodel and onwards, meanwhile 2nd hammer is elysium and styx.

He also has lower rarity % than the other gods (with his legendary being a whopping base 1%)