PowerHerc

 1.  Hercules (Marvel)  
 2.  Thor 
 3.  Cuchulainn (31st century Guardians of the Galaxy) 
 4.  Big Barda 
 5.  Odin

 6.  Darkseid
 7.  Orion

 8.  Zeus (Marvel) 
 9.  Lightray 
10.  Highfather  
11.  Valkyrie 
12.  Leir  
 
Too bad the Eternals aren't Gods, or I'd have put Sersi, Ikaris, Thanos and Makkari on the list.

I think he's easily right where he should be in terms of power and perception thereof.  He's a top-level all-around powerhouse and top-level in strength, speed , durability, energy manipulation and experience.  He's not always properly used, but that can be said of nearly any character.  He's not under or overrated.

Juggernaut.    
 
The Ruby of Cytorrak makes him totally indestructible.   
Nothing can stop or destroy him.  This is his main power, even moreso than strength and stamina. 
He's more durable than Gods, Cosmics, Heralds of Galactus, Eternals, etc.   
Though he can be hurt and even defeated, he is immune to physical destruction.   
He doesn't need to heal or regenerate like the Hulk, Wolverine, King Hyperion and others. He's always indestructible.