HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

The question wasn't pulled out of thin air; I've actually seen and used this feature. Either in Heroes of Might and Magic or Warlords... I've forgotten which.

There is such an option in Heroes of Might and Magic, but you can't replay the autobattle there. In fact, autobattle with magic can be useful in isolated cases.