90% of the artifacts on each of the maps are random, except for ones that have been specifically specified by the developers. Now, you can also assemble other combination artifacts outside of that mission. The Air Cave will give you the Power of the Dragon Father, the Fire Cave will give you the Wizard's Well, the Water Cave will give you the Ring of the Magi, and the Earth Cave will give you the Bow of the Sharpshooter.

There are seer huts not marked on the map in the other underground chambers, each one gives you a different combination artifact in exchange for the Elixir of Life (Which can be obtained in that mission). G# - Guard Tents (a) and the location of the Guard Tower (b) S# - Seer(a) and the location of the item (b) O# - Opponent Towns (a,b,c,d,e,f,g indicates which enemy) In 'Fall of Sandro' in Unholy Alliance, you can trade in the Elixir of Life for other combination artifacts at a seer's hut underground. Yes, it is possible to assemble other combination artifacts in Shadow of Death.

Heroes 3 combination artifacts