But as long as the Warmech can cast NUCLEAR, and my Knight is still stanging afterwards, it leaves me to believe that HP represents not the HP of a boxer, but more like the amount of lives you have.

By that logic, I'd say that a man with 70,000 HP could withstand an atomic bomb in our world. And a bullet wouldn't do more than 30-100 damage, depending on how many crucial organs it manages to pierce.

If we had FF HP in this world, and it grew with level, I'd sing on my way to Iraq.

Of course, we'd all start with 1 HP, so it'd be a hard build up.