Mimic is already doing a lot of work & I don't want to change stuff on him; so for now we can keep moving ahead with the implementing designed Heroes as planned, with the one change that they're ineligible to earn most of the generic unit promos as you described below.
We can also leave the standard +1 XP from the FfH Hero promotion as you suggest, and not need to modify the current Champion/Lord promos Mimic has implemented.
Agreed. The 1 mod to the hero promotion we might want to change is to implement it to give immunity to psychology/fear effects.
Also; huge HOMM fan, I loved those games. And that is very much the inspiration for the kind of promotion chains I am thinking of.
Quick draft of a few possible chains:
Tactician 1. Requires [Footman OR mounted]. All units in the stack gain +5% strength and 1 first strike chance.
Tactician 2. Requires Tactician 1 AND [Champion OR champion of chaos OR venom champion]. All units in the stack gain +5% strength and +5% withdraw chance.
Tactician 3. Requires Tactician 2 AND Lord. All units in the stack gain +5% strength and 1 first strike chance and +5% withdraw chance.
Administration 1. Requires: [Champion OR High priest OR champion of venom]. Gives +1 happiness, +15% hammers, +1 health to cities in range 1.
Administration 2. Requires: [Champion] AND Administration 1. Gives +1 happiness, +15% hammers, +1 health to cities in range 5.
Administration 3. Requires Lord AND Administration 2. Gives +1 happiness, +15% hammers, +1 health to cities in your empire.
Siegecraft 1. Requires: [Footman OR Champion OR Champion of chaos OR venom champion] Gives +5% city attack, +5% city defense to all units in the stack, increase bombardment of all units in the stack that already have bombardment +5%.
Siegecraft 2. Requires Siegecraft 1 AND [Lord OR Dwarf or Chaos dwarf]. +5% city attack, +5% city defense to all units in the stack, increase bombardment of all units in the stack that already have bombardment +5%.
Siegecraft 3. Requires Siegecraft 2 AND [Dwarf or Chaos Dwarf]. All units in the stack ignore city walls.
Weaponmaster 1. +15% strength. Requires [Footman OR Champion OR Champion of chaos OR venom champion OR high priest]
Weaponmaster 2 +15% strength. Requires [Champion OR Champion of chaos OR venom champion] AND Weaponmaster 1
Weaponmaster 3 +1 strength. Requires [Lord OR Favored of Chaos OR venom lord] AND Weaponmaster 2
Healer. Requires [High Priest OR Archpriest]. Gives +25% heal rate to units in the stack.
Swoop attack. Requires Aerial mount. Gives 1-2 first strikes.
Heroic charge Requires Mounted AND [Champion OR Champion of chaos OR venom champion]. Gives +10% attack strength, +10% withdraw chance.
Summoner. Requires [Archmage OR Warlock OR Sorceror]. And some heroes start with this. Summoned creatures start with Strong promotion.
Another idea: we can have some of the various Mutation promotions we were thinking of (scaly skin, extra arm, fiery breath, etc.) come not just from mutation effects but as purchasable promotions that require the Demon racial promotion.
That way, ordinary demons can pick them, and demonic heroes can get them too.
Or we could have them require [Demon OR Favored of Chaos]
There is so much we can do by messing with promotion requirements.