One of the first things that I noticed was that Hierophant which is similar to Archmage but for diviners, can be cross-classed with anything. With the Practised Spellcaster bug fixed and a shift closer towards PnP, can this restriction be removed for Archmage?WARNING/NOTE: This class can only cross class with the following: Arcane Scholar, Frost Mage, Pale Master, Red Wizard, Harper agent, Blood Magus, Sorcerer, Shadow Adept, Thaumaturgist or Wizard
Lore-wise, the class is not restricted. Elminster himself has Cleric, Fighter & Rogue levels along with Archmage levels
I feel that with mages needing a high casterlevel (what is it now, 27 or 28?), that Archmage can provide more build options. The spellpower abilities also cost spell slots (which Hierophant's does not).