Time for some more pics:
This is the barbarian army in question. My lands are on the right just over the bridge. Go away.
My onis in search for roasted newt (invading C'tis). It's quite zoomed out but you can make out my casters on the left - mainly hannyas chucking fireballs, then some blobs of green and red oni (fire-cold based), and sone enlarged ants in front. The ants are there to soak up some of the trampling C'tis chariots. Units can only trample other units of lesser size, and they are both 4. As you can see I got a huge numerical advantage and way more casters - C'tis had only 2 priests and a 2D and a 1N1E caster, so I stomped them into the ground.
Fire Ant. Nothing to write home about but decent HP and protection make up for a good sponge. Mindless adds to that by being impervious to various control and fear magic. Their magic resistance sucks though.
Fireball obliterating a tile of lizards. 16,9,22 damage to the 3 units inhabiting the square.
Aka-Oni (fire) incinerating Lizards.
Magic armor. It has low protection but no penalty to defense or encumbrance and confers 20 stealth. Sweet for equipping non-stealthy thugs with crappy default armor (Oni Generals or Dai-Oni) to sneak behind enemy lines and then strike many different provinces at once.
This robe provides etherealness. It boosts innate stealth, but does not provide non-stealthy units with it.
Ok there I made some mistake. It's rather expensive for this stage of the game to outfit Supercombatants, since there are not enough gems or high-level magic items available. So I ended up with a rather expensive thug (in theory a cheap raider). Nonetheless he kicks some serious arse. He got a waterbreathing ring so I could take the underwater lands adjacent to my capital at last. He also got into the hall of fame and Iron Will as heroic ability - which is kickass since magic resistance is a prime defense versus many SC counters.
That's it for now, I hope the other players will update on their game too!