Regarding Zeus' reasoning

[Kepekley23]

What states Saint Seiya Zeus to be "far" above Cronus? He defeated him on a large-scale battle, possibly with the help of his brothers (although this is unknown). Cronus, upon releasing his unsealed form, stated that he'd kill everyone on Earth, including and specially Zeus.

 

[ZacharyGrossman273]

Agreed

 

[Crateris_Aeson]

In StS Episode G it is described that Zeus (alone) defeated and sealed all the Titans when he obtained his weapon, kerunos or lightning. In Assassin it is described that the battle against Zeus is the final battle of the Saints.

Zeus with lightning >>>> 12 Titans

 

[Antvasima]

You should ask Matthew Schroeder to comment here.