I think the order should be "The Restoration of Erathia," then "The Shadow of Death," then "Armageddon's Blade," and only then "In the Wake of Gods."

Erathia, then Armageddon's Blade, then The Shadow of Death – think about it: in Armageddon's Blade, sets are collected, and if you find the last artifact with an empty slot on the hero's equipment, plus the other parts are equipped, plus 4 slots for "miscellaneous" artifacts in Armageddon's Blade. The Conflux is only there because that race exists in the campaign. Next, In the Wake of Gods (the official version seems to have been released under the 3DO label, and then I personally saw the "Life vs. Death" disk by Fargus, but the add-ons for version 3.5 were authored by Vog, and they weren't on disks). Chronicles is separate (after SoD). I've heard unreliable information about the very first part of Heroes 3, just Heroes 3, if anyone knows about its existence, please describe its campaigns if such a part exists.