We both had two armies. I (Pontus) was seiging the last Armenian city, which had about 200 troops inside. I had a force of about 4 phalanxes, 3 archers, 2 light cavalry, 3 scythed chariots and a general seiging the city.
They had one army inside the city, about 3 generals, two eastern infantry and horse archers. Their second one was something like 8 eastern infantry (full health with weapons upgrades) and horse archers. So I built another army, consisting of mroe phalanxes, pelsats, and scythed chariots.
I merged these two armies outside the city. One had my infantry troops, the other had all of my scythed chariots (about 6) two hoplites one archer and a general. I used my infantrymen to seige their city (Artaxarta, their capital and last city) and tried to pursue their Eastern Infantry army.
They attackded my seiging army outside the city, which had about 400 troops. They had 200 in the city and 300 attacking me, so they outnumbered me. I auto-fought the battle

blush:) and won with only about 40 casualties (one of which was my general). I maintained the siege, but they still had most of their trooops in the city.
Here's where my slaughter comes in. Awaiting this moment for a couple of years (years in the game, actually maybe half an hour in real life

)
We met on the battlefield the next turn. My scythed chariots against their eastern infantry. Their reinforcements came from inside the city and my reinforcements came from the army sieging the city. Because of the size of my seiging army, I only got to use 100 or so troops from them.
They started in the trees at the bottom of a hill, their infantry in a line. I grouped my scythed chariots and archers into two groups, my charioteers approaching their flank while my archers shot from the front. I massacred them, but they had their stupid horsearchers firing at me and killed a few of my archers.
Then their reinforcements arrived behind me, so I had to turn around and fight. I kept two companies of scythed chariots (about 17 men) behind to disperse of the routing eastern infantry, and moved everybody uphill to the other side of the map. My archers were pretty tired, but had to exchange arrows with horse archers from them, who ran away every time I shot at them . Then I had my charioteers flank them (again!), while my hoplites had to absorb a charge from eastern infantry (not pretty). I killed their general (and faction leader) and still had plenty of troops to spare.
The battle wasn't over yet. It turned out their first horsearchers (about 9 of them) were still stalking the woods, harassing my charioteers, who were standing still. I had to kill them off with archers, all but one. That one I had to chase down with my exhausted charioteers half way around the perimeter of battle.
Overall, few casualties. About 9 people, while I destroyed all of their troops and, simultaneously, their faction.