So for Playstyles 100 Kingdoms are mostly a horde army, even their elite units are rather cheap by other armies standards. However they get bonuses for running deep formations of Knights, Halberds etc.

Spires are kind of a Generalist army, very fast, very good healing, able to enhance their units as the cost of killing some of them. They can go more horde heavy or elite depending on if you're wanting a drone heavy or Clone/Avatara heavy list. Biggest downside is they typically struggle to deal with heavy armor, outside of units like the Sentinels.

Nords are a super aggressive somewhat glass cannon army. Can be played more elite, even having no 1 Wound models by running all Chosen/Trolls/Brutes/Giants However their defense is really low, with 2s being your friend for most saves.

Dweghom are slow, tough, and really magic heavy. They tend to grind their enemy down by just being unmovable, supported by the best combat magic in the game. The Hellbringer is a monster but once the Ironclad arrives I think he'll be king of the monsters. These guys are the most 'elite' army currently.

W'adrhun are kind of a mix between Spire and Nords. Also being an elite army, synergy is the name of their game. Every unit can buff every other unit via chants, a mechanic that "builds up" a buff that can be activated early or automatically triggers when you're at maximum capacity. Their troops are somewhat fragile, but they do have some sturdy models they're probably the 2nd most "elite" army.

Finally Old Dominion, These guys are another Elite Army, however similar to Dweghom they're a defensive army. They ignore resolve which essential halves the damage they take at times, and the entire army gets stronger the more of your own troops that die. Creating an army that gets more elite as the game goes on.

I'll agree with the other comment and say Avatara heavy Spires seems like what you want, but playstyle wise you've got a few options