I enjoyed the reenactment of the forum discussion between Jonny and me.

Regarding AI-controlled Peter and his movement: His level of aggressiveness isn't random as was speculated on the show. I actually touched on this a bit in the discussion thread.
Oh, if an enemy enters his attack range he'll kill it mercilessly. But that never seems to happen because if there's nothing he can attack immediately he only moves a square or two instead of to the end or his range. It seems the CPU is unwilling to put Peter into an enemy's attack range unless he's attacking another enemy. I suppose it's for the best because it would be rather infuriating if Peter kept dying because the CPU was too aggressive.
It's the same way with the enemy characters, which is why each battle is composed of several skirmishes instead of one giant battle. For the most part enemies won't enter your attack range unless they can attack you first. They'll hang back on the battle field until you wander within their movement range. Since there's no incentive to beat battles in a limited number of turns it's possible to game the system by moving all your characters just outside of their range and then luring them to slaughter with one strong character.