Oreaid:
Or astral 9 or 10 for twist fate.
Some research required (const2, evocation2, alteration2). So use philosophers and sloth. You don't need more than one resource for building Oreaid anyway.
Build order:
Turn 1: Oreaid
Turn 2: Philosopher + build troops
Turn 3: Oreaid + build troops
Turn 4: Philosopher + build troops
Turn 5:.... and so on.
Research
Alteration 2
Evocation 2
Construction 2
Equipment:
Shield of Valor
They can forge it themselves. You will have the gems needed after you've researched the above. It won't take many turns, expand with your main army in the meantime.
Total cost: 400 gold, 5 earth, 5 air
When you are ready you will have about 4 Oreaids and 4 Philosophers. Use your scout as prophet and put on the shields on the Oreaids. With your scrying and stealth scout prophet and Oreaids you can choose freely which provinces to attack. Why not backstab another player in his rear territory?
Script for Oreaids:
Barkskin/Stoneskin/Resist lightning/Shock wave/Shock wave/Spells or attack.*
*Use only if you later equip them with some nice weapons. Don't worry, there will only be archers left on the battlefield anyway. No you shouldn't attack a whole army with these gals alone. If want to, use backup.
Script for Prophet
Divine blessing/Smite/Smite/Smite/Smite/Cast spells
Placement:
Oreaids on top of each other middle extreme forward. This is important because you want that lightning to really devastate the enemy in one round making the few survivors rout. No, it isn't likely they will get hit by arrows (they have parry 8*2 + air shield 80%). If you are really worried about this, use mist (evocation 3). The turn later they will also get twist fate and barkskin. The turn after that stoneskin, giving your Oreaids protection 15 on the whole body (later you want to combine this with light weight scale mail and black steel helmet giving you 23 prot).
Turn 3 the Oreaids will cast resist lightning and the enemy will be upon you maybe trying to strike you. With 17 defense, protection 15, awe 5, and twist fate they will not harm you - promise. But don't attack anything with very high morale until you get more equipment. Remember, this is early in the game and you got a very potent elite strike force with stealth, seduction and electricity. There are plenty of juicy targets. The joy.
The prophet should of course be placed very far back to avoid anything stupid.
Try it. These gals have loads of potential in close combat. There are also lots of nice spells and weapons later in the research tree. And if you want to attack evil mind burn mages, the Oreaids MR is nothing to sneeze at and doesn't get worse with the astral bless.
Shockwave is a nice spell. But now something completely different...