I imagine/assume you guys are discussing EA Oceania with CBM 1.6 in mind.
Imo EA Oceania is one of those nations crippled by the unique gem gens, since they just cry out for clam and fetish factories...I was thinking of doing a guide for them (vanilla) called fire and ice, but I'm lazy.
The general idea is how to get onto dry land, and imo for EA O it's all about evocation spells...falling frost spam + falling fires spam + ice strike spam (late game replace with niefel flames + flamestorm). Your troops aren't that great and tricky to mass (the high prot ones anyways)/buff, you've got to kill your enemy before they get a chance to kill you. With 3 different damage dealing spells...well chances are your opponent will have to work pretty hard (and might not be able) to adequately protect against all 3.
The pretender chassis I was playing around with was a sleeping arch mage,
O3P3C1
F3W2E3S5D2 dom4
-not too concerned with dom4 since you'll have a crazy amount of money to buy forts and temples (spam them hard). If I recall I came to the conclusion that the best way to maximize the production scales was to have a fortress in every water province I had (long term goal) seeing how the administration for the UW forts is so sucky.
-F3W2 so I can boost up to staff of elements
-E3 for hammers
-S5 to boost up to S9 and then drop my pretender around (with amulet of fish+ritual of returning) for master enslave. Or just drop him around for fire storm, etc.
-D2 combined with F to get skulls of fire, combined with W to get the kokythiad, also to find those D sites under the seas so I can get leviathans, and the rest of the good D stuff
-Also when looking for thugs, I went sea king court and then GOR'd the sea trolls, and just left the sea king to generate W gems to pay back the summon (slow payback I know
)