ezo
Hero
While an Ogre might be a boss at low-levels, maybe a leader of some bandits or marauders, that Ogre could "report" to a more powerful creature, such as a Giant, and later on be met as a mook in service to the Giant.
It is no different than criminal organizations where a sub-boss might be met by a beat cop, and later on the beat cop is a lead detective and meets that same "sub-boss" but who is now shown to be a "mook" in service to a mafia don or something.
The sub-boss might have even learned a few new tricks and so be more powerful than it was before, so it is still somewhat of a threat to the lead detective.
It is no different than criminal organizations where a sub-boss might be met by a beat cop, and later on the beat cop is a lead detective and meets that same "sub-boss" but who is now shown to be a "mook" in service to a mafia don or something.
The sub-boss might have even learned a few new tricks and so be more powerful than it was before, so it is still somewhat of a threat to the lead detective.