These subtypes might be able to have useful mechanics tied to it.

[minion] subordinates with little self determination

[mundane] non-heroic/epic/mythic

[sidekick] represents someone whom would be a lower tier not for their relation to a higher tier.  This represents things like familiars, animal companions, cohorts and the like

[heroic] represents key actors in the story of the world, be it heroic or villainous nature.

[epic] would probably consist of heroics when they achieve a certain level.

[Epic II] Heroes who have traveled in their personal Professional journey beyond common levels of power

[mythic] is defined elsewhere


Probably more work to go
This message was last edited by the GM at 09:01, Sun 08 Jan 2017.

I don't think you want to tie these tiers to ability scores... that would be far more of a choice that might occur, but not part of their nature.

Types

 -+ Dependents [Having an altered status/type due to a relationship with some person or entity]
  +- Minion [normally attached to a villain]
  +- Servant [above the purely mundane via service to an entity (settlement, army)]
  +- Companion [elevated above mundane through association with a heroic+]

So minions are almost sub-mundane, at least in effect, at least in conflicts.  A point I'd like to suggest is that Minions do not have 1hp, but rather they 'effectively' have one hp or 1hp per die.  In some or perhaps even many, they may have 1hp, but any hit that takes down a minions effective hp makes them a casualty.  The exact nature can be cinematic and could take any number of effects, from being cleaved in two, to stabbed and falling down, to fainting due to the pain, to even scaring them into fleeing by slicing a thin cut on their face/hand/stomach.  If a 10HD giant can be a minion, is it acceptable to make a 5HD wizard a minion, overriding its previous status of being once non-mundane via some other relationship.

Heroic
 Including those self-defining characters of good/heroic nature or evil/villainous nature (or otherwise).  It also transitively may apply to those Companions of Heroic individuals.

Epic
  Implication of Epic is of proven Heroic characters whose power level has a far wider implication.  [I'm pretty sure that 3.5 had epic DR for instance, where some creatures required a certain amount of significance in that way before they became vulnerable]

Mythic
  Includes a dab of the divine or fate.  Mythic implies Heroic, but may come about before reaching Epic.  However, Epic might get accelerated by Mythic potentially. 
This message was last edited by the GM at 08:54, Sun 08 Jan 2017.