Seems like everyone is getting a nice Shield Guard unit these days.
A 3 or 6 man unit could have a nice place in Exalted - Immortals fill the 10 man slot. Small unit sizes are good for abilities Battle Driven, Sanguine Bond, Unbreakable Wall, Wall of Steel, Defensive Line, etc.
To build off your Archer idea, "Counter Attack [Ranged]" (real surprise with Shield Guard)
i like the idea... though i feel like immortals should only really have 1 abilty per unit. their stats and [soul vessel] do the rest. they shouldnt be an overly frustrating army to play against, either.
cav- battle driven, spd 6 [good for stone people]
cataphracts- sheild guard, 18 am, 10 hp
archers- counter attack [ranged].
also, i hope we do see an epic mordikaar emerge as the other exalted caster. have him deal a lot with souls in different ways than zaal. maybe a feat like:
soul rage each model with soul tokens on it gets +1 spd and str for each token currently on it. whenever you spend a soul this turn, put one on mordikaar.
I’ve also thought of a possible WA for archers based on the old multiple rocket launcher systems the medieval Chinese built. Something like: Range 14 Pow 14 4” aoe Choose one: Brutal damage High explosive Knockdown