Third: VH on battle map means simply, the unit balance doesn´t exist anymore as it was ment by editing the EDU. The AI ain´t become smarter but more of a killing machine with +7 bonus on attack, defence and morale values.
And last but not least: when you take out an AI commanding general, especially such as Pyrrhus with his 8 stars and troop morale boosts, you will allways weaken enemy significantly, and only VH settings prevent it from fleeing in panic after you press them from all sides. So, if you want a realistic fight don´t go after the commanding general ( a human player would have lured you in a trap, i gues, if he would see, what you are planing

)