Following on from my posts on core and special.
No rares.
Not as such.
Basically, I'd have an array of "rare units" which can be chosen, depending on the hero/lord choice of an empire army.
For example:
If you have an engineer in the army, you can choose up to two of the following:
- Rocket battery
- Hell fire volley gun
- Steam tank
If you have a warrior priest of Sigmar in the army, you can choose up to two of the following:
- Flaggallants
- War alter (one only)
If you have a Kislev captain of the North in the army, you can choose up to two of the following:
- Kislev cossaks
- Whatever
Etc.
Meaning, if you have a warrior priest and an engineer in the army, you could have two units of flaggies and 2 hell fire volley guns.
Power / cost would have to be adapted for balance purposes.
I find, however, considering the size of the empire and the diversity (and allowing for individual choices, etc.) that this system would benefit the tweaking and individualisation of the armies.
Don't forget though, I don't think empire "men" should be strong, exceptionally brave, or anything. The choice and detachment rule are what balances the game.