Ramuh was an exception as he was the only Primal who thought completely different from the rest. Shiva seems clever and thoughtful too I expect to see more complicated dialogues with her in cutscenes.
Odin was quite a big disappointment. He supposed to be something really powerful yet he downgraded to a simple fate mob without any proper cutscene or dialogue and lore.
If they are to put Alexander in this game its gonna be weird. Ishgard doesn't seem like a technologically advanced civilization like Allag so I will be curious to see they summon Alex or sit on him. Alexander supposed to be something huge and holy. It will be strange to see him act like the rest of the primals for destruction. I would rather see him protect the kingdom or Ishgard from something sinister like the Ascians or Bahamut (if he ever returns ofc) or against Omega. Though with Omega we will have 2 huge Mechs fighting each other gonna be really weird for the mostly medieval world of Eorzea.