Another thought on this is divide the Egi's Glamour system up into two caterogies; Melee and Ranged. In this way the community doesn't have to guess if you are using Summon I or Summon III and the dev don't have to try and make each Egi into a once style fits all approach. Starting now Titan and Ifrit would be melee and Garuda would be Ranged; Carby is what it is and shouldn't be changes.

Melee:
Leviathan
Ravana
Sephirot
Susano
Zurvan

Ranged:
Shiva
Ramuh
Bismarck
Sophia
Lakshmi