Artifacts in Heroes 5

The main thing is that artifacts exist... The game is still under development, but there are already a decent number of artifacts. I am more than sure that there will be many more than there are now. Although in the third game there are 123 artifacts (with and without the scroll of magic, and including those that are assembled from parts), and in the fifth game, only 54 have been revealed so far... On the other hand, in the third game, there are many similar artifacts that give practically the same bonuses. Tell me, what is the difference between the Helmet of Chaos (Intelligence +3) and the Crown of the Archmage (Intelligence +4)?