Assembled artifacts in Heroes of Might and Magic V.

The coolest thing is that you don't even have to collect them all! For example, I collected 2 Arantir artifacts in the campaign, and the Banshee's Cry was so enhanced that I didn't need the other two artifacts, or even the Cry of Terror. I don't know how it works with other sets, but in the Dragon set, you get +1 to the hero's stats and something else for just 2 items – is that bad?

P.S. Later, I found the Necromancer's Amulet (along with a cloak and something else) for Arantir, but I couldn't find the staff (I searched all the shops and Utopia) – where did they hide it?

By the way, I had this weird thing happen: I leveled up the Cry of Terror, and I had a half-set of Necropolis items (2 items). The Cry of Terror refused to work even after I took off those 2 items. Is this a bug?

P.P.S. That is, the Banshee's Cry remained as if I had a full set all the time (even after I got the Cry of Terror and removed the artifacts)!