"The cherubim went in whatever direction the head faced, without turning as they went. Their entire bodies, including their backs, their hands and their wings, were completely full of eyes, as were their four wheels."

they look very scary in this image here:

https://medium.com/old-pink/the-beauty-of-the-seraphim-1b4613e1226b

but to be fair we have the chaos wastelands, disgusting demons in warhammer already lol.
so i don't see what the problem what would be with having scary angels, which could have traits that could easily route warriors of chaos to.

**this is just to help you with some other ideas so, i also think that for any "Archangel" units could be one man units that can fly / land & could deal wield, give leadership to nearby units, maybe even heal regen other units, since the chaos demons one huge one man demon units that are absolute tanks so it would be perfect to have this faction have a similar "Archangel" be their counterpart.

another last idea for campaign is obv corruption, increase replenishment to your units / allies, maybe they give massive growth to allies or your unit factions? with maybe some public order as well.

i think the last thing that i recommend to make it easier for you would be to create "Ascended" units, as in their the same as some base units but also with increased stats, like armor piercing, unbreakable, etc, for more money but with less unit counts compared to the regular copies. i also don't see why they can't have something inbetween the chariot unit that the Britonnia which helps morale, but something that the Vampires have that can also heal nearby units but not to broken where they can do both perfectly, since their Angels & are supposed to represent Hope, Light, Healing, Faith, but clearly in a world filled with fighting are not afraid to fight as well for the realm of light.