I started by retreating my army minus the general towards the big hill. I figured this would give me the best position to hit them with missiles for as long as possible before the armies engaged. My general stayed back to be a pest and lure the enemy into charging and wearing themselves out. The advantage you have is that your General's Bodyguard is faster than their Eastern Armoured Bodyguard, so you don't have to worry about fighting them. The only units that can catch your general are the horse archers, so he'll be fine. I just ran him around trying to find weak points so I could rout a unit or two.
In the second phase of the battle, the enemy had reached the bottom of the hill and were being hit by Cretans, Archers and Rhodians. I focussed on the area with the most troops, because my missile attack was high enough to cause a lot of deaths because of the inferior Armenian defence - as long as they hit. The phalanx line was only four men deep to give me a bit of extra coverage on the wings. I was banking on their units being exhausted and charging up a hill to prevent them from breaking through. In front of the phalanx line were the Rhodians (so they didn't hit them in the back due to their horizontal firing trajectory) who acted to lure in the enemy Armoured Bodyguards. Unfortunately for them, I forgot about they were sitting there while I concentrated on other things and they didn't escape the charge. My general was sitting behind the army ready to charge downhill to wherever he was needed.
Here's the first screenshot I took:
I'll explain what's going on. On my right you can see a lot of routing infantry. These were routed by exhaustion with fire arrows. Once one of them began to rout I knew that the others would soon follow so I turned my right phalanx inwards to help with the incoming Armoured Bodyguards. On the left, one unit had flanked my phalanx, so I shot one volley of fire arrows and then had my General charge and rout them.
At this point of the battle I just routed their king. It really helps to have them charge incredibly slowly by making them go uphill, while exhausted and the fact that they aren't fast moving like other bodyguards. This started a rout that included most units except the Faction Heir, but he was heading towards the Phalanx Pikemen, so I wasn't worried. All the while, my archer units were firing normal arrows now to ensure that the enemy didn't rout completely so that my general could chase them down on their way back to the settlement.
Here's the army running down everyone they can overtake. Archers are especially good for this because they are fast moving and often not as tired as melee fighters.
And the result. Plenty of carnage for archers. It seems unfair that the second unit of Cretans didn't get any experience. They certainly deserved it.