Artifacts in Heroes III.

I apologize for deviating from the topic, but I want to say something about "Dungeons and Devils."
I also couldn't beat Steadwick in the last mission, but I did something quite simple: I bought a bunch of heroes (there was a tavern nearby), sent them near the castle (some a little closer, others a little further away), and when the computer's turn came, it simply went to eliminate them, and then I just entered the castle with another hero.