[Fantomen]

Kokythiads and Naiads seem central to this strategy, so water is definately a must to follow this guide. Then there's leviathans and hidden in snow etc.

I'd like to emphasise how much nice spells you have in enchantment that synergises with this way of playing Oceania.

Strenght of giants, raise dead, dragon master(for your naiads to spam ice drakes), clay men, fire/winter ward, quagmire, foul vapors, water ward, grip of winter, rigor mortis, relief, life after death, leviathan, serpents blessing(with foul vapors), Warriors of muspel/neifelheim, mass regeneration.

I´d make enchantment the third priority next to conjuration and alteration.

Also, the deep shambler has three attacks and higher protection, hp and strength than the deep one. Not saying it is a better unit in general but if you are purely looking at damage output/hp per square early on or are facing battlefield wide damage spells it can be better.