I’m not too familiar with the different realms so I’ll just come up with what I think would look cool and defiantly draw my interest back to AoS.
The realms were formed from the winds of magic after the shattering of the World that Was, so there are 8 corresponding to the old lores of magic. E.g Aqshy, the Realm of Fire, and Chamon the Realm of Metal
1-Steam punk, with lusts for gun powder, steams tank technologies, war wagons, GUNS, BIG GUNS, airships, etc. Think of Leonardo Devinci schematics.
There are currently 2 factions that are quite steam-punk, the Kharadron Overlords - flying airship dwarves, that looks very steampunk, and are somewhere between traders and privateers. For humans, together with Duardin (dwarfs), there is the Ironweld Arsenal, who build war machines to protect the free-cites, and have built huge walking constructions called Cog-Forts (walking castles).
2-Air Pirates, these have their own version of airships (pirate ships) ragtag bunch of mercs. with no alliance but to those who can pay the highest price for services. Individual raiders with bat like mechanical wings in which they launch themselves off the ships to attack venerable objectives. Raiding parties, ship boarding, stuff like that.
As i've already mentioned, there are the Kharadron Overlords - with their steampunk style airships, but there are also rumours of Grotbag Scuttlers - goblin sky pirates, think of very old John Blanche artwork with flying wooden ships. I don't know if there is much credibility to those rumours though, but they seem to stick around.
3-A realm where magic and technologies rule supreme. Wizards lead and have henchmen or assistance to help protect them from harms. This is where you would have War wagons that represent all colleges or winds of magic. Warrior monks, secret assassins etc.
All of the realms are highly magical in some way, and there is the both the Eldritch Council (What was high elf mages) and Collegiate Arcane (Human Battlemages), many of these are based in Azyrheim the great city of the realm of Azyr, where Sigmar once ruled, and was cut-off from the rest of the realms during the Age of Chaos, to protect it, and from where the Free Peoples set forth to re-establish cities in the other realms after the Sigmar sent his Stormcast Eternals into battle for the Realmgate Wars. In the same place, to protect from corruption is the Order of Azyr, the Witch Hunters of the mortal realms.
4-Classical People that are trying to rebuild the empire and have created city states that represent the way things used to be ( to their best ability).
After the World That Was got destroyed, and Sigmar found the realms and the people who had survived and found themselves there, they build great empires during the Age of Myth, including the Lantic Empire, the largest of all of them, though all of those fell in the Age of Chaos, but the settlers from Azyr, seek out those old cities, to rebuild, or found new ones - the background story has moved on a few hundred years since the game launched - And now there are many great cities - Hammerhal, Hallowheart, Phoenicium, The Greywater Fastness, The Living City, Exceslis and many more. And they are protected by the Freeguilds in the main, but also support from the Collegiate Arcane, Ironweld Arsenal, Stormcast Eternals, and other forces of order, though not all is peace and harmony between the forces of order.
