I like the idea, but as a computer programmer I think it could have been implemented much better as a list of weighted priorities rather than a round-by-round list of actions. The list as presented is not practical because there is no accounting for the response of the opponents. I would have liked to see something like this:
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Combat Tactics
The pit fiend opens with spell-like powers, attempting to neutralize dangerous opponents before entering melee combat.
Preparation: Unholy aura; activate fear aura, quickened summon Baatezu.
1st Priority: If in danger, use greater teleport to flee combat.
2nd Priority: If outnumbered, use mass hold monster to even the odds.
3rd Priority: Keep potential spell casters neutralized using power word stun
4th Priority: Weaken tough opponents with meteor swarm
5th Priority: Full attack to finish off the weakest targets
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The pit fiend doesn't do these things in order. Typically, it will perform actions higher up the hierarchy, and actions lower on the hierarchy when none of the higher options are applicable. This gives the DM some idea of what is most important to the Pit Fiend as it fights instead of a rigid list that only works in a very specific situation. It's more flexible. It's also one method one might use to model simple behavior effectively in AI for computer games. I think that the parallels in utility here are clear.