So by "strength" you only mean lifting capacity? That would have been a useful thing to know, because that is so narrowly defined that it changes the entire point of your post. (and also has nothing to do with your NPC stuff, but we are moving on)
Sure, an Ogre with their 19 strength can lift a thousand pounds and a human can only lift 600 lbs. But the point isn't whether or not lifting 600 lbs is superhuman strength. The point is this:
The human lifts 600 lbs
The elf lifts 600 lbs
the dwarf lifts 600 lbs
the Warforged lifts 600 lbs
the half angel lifts 600 lbs
the half demon lifts 600 lbs
the half earth elemental lifts 600 lbs
the gnome lifts 600 lbs
the half vampire lifts 600 lbs
The Minotaur lifts 600 lbs
The idea of a human limitation makes less sense when you realize that being a vampire-blooded minotaur... doesn't make you stronger than a DnD human. Dante and Vergil from Devil May Cry are able to do things like catch bullets on their sword and fire them back by swinging the sword, and that is because they are the children of demons, but being the child of a demon... doesn't make you stronger than a DnD human.
So, this conception that we need to limit non-magical martials because of human limits... doesn't make a lot of sense. My fighter could be a child who was blessed by the god of war (Aasimar) and they would be no stronger than the farm boy fighter who left to impressive the mayor's daughter.