I don’t like the idea of having a second added on campaign nor do I like the idea of changing the story of the original campaign.
But are there ways to have at last some missions have you fight other civilisations?
The first 2 missions are Tutorial Missions and the Greeks are the most simple and “AoE” like civilisation. So those should not be changed.
They are also the only missions where you fight against Egyptians as Greeks.
The city of Atlantis could use the Atlantian civilisation though.
Mission 3 to 6 let you fight the Trojans. They are represented by the Greeks but they aren’t really Greek. If a Mesopotamian civilisation would be added they could replace the Greek enemies but let’s assume that is not the case.
There is no real way to change the missions. Troy is clearly not Egyptian and definitely not Norse or Atlantian.
7 let’s you fight Bandits that are Egyptian again.
In 8 you are in Greece so it makes sense you fight the Greeks.
9 and 10 are in the underworld and neither you nor the enemy has a base.
11 to 15 are in Egypt and you only fight other Egyptians. I don’t really see any opportunity to change that. With a lot of fantasy you could change up one mission to add Chinese or Greeks as enemy.
16 is the dream where you attack Atlantis. Atlantis should clearly be replaces by the Atlantian civilisation here.
17 is a full Egyptian mission again.
18 is interesting because you get Ox Carts and some Norse units while playing as Egyptians as a mini tutorial for the upcoming Norse civilisation.
19 Is a full Egyptian mission again but you have Greek allies that give you Colossus. So there is some diversity here too.
20 Is the final Egyptian mission.
21 Is a funny side mission that lets you play as Greeks against Greeks again. Can’t really be changed either.
22 to 29 are all pure Norse vs. Norse missions. Other civilisations are only used for players that don’t train units.
30 has you fight against Greeks as Norse. Maybe Greeks could be used in some of the earlier missions too. Hard to justify using Egpytians or Atlantians.
31 and 32 let you fight Greek as Greek again. The enemy Atlantis should be replaced with the Atlantian civilisations, or maybe Atlantian plus Greek.
There is also the option to add 1 or 2 missions inbetween some of the existing ones to mix things up without really changing the story.
But I don’t think they should be dream missions again.