What is more important: luck or fighting spirit?

A little off-topic, but I'll still say this: I recently played Heroes of Might and Magic II and took both the "Leadership" and "Luck" skills. I thought, "Now I'm going to be awesome." But after some time, I found an artifact, and it was so good that I even felt a bit annoyed...
...it was a shield, and it was already assembled. It increased morale and luck to the maximum, and also gave the "Portal to Town" spell with the option to choose which town to teleport to. With such an item, you can save two slots!