Well if we're gonna be like that, I can clean & jerk more than a buck sixty and it'd count, no? The description says the most weight a character can get over his head and walk a few steps. But I agree..."It's a very different workout when you have to use your back, your legs, and your core... instead of merely the pects and arms." Thats why clean and press is the best measure, IMO.
Though, fact is I suppose, your legs are always going to be stronger than your upper body, so your "max press" is limited by your shoulders, back, chest, and arms, and not by your legs.
Edit: Oops: "You'd have to do proper carrying capacity and drag capacity" Missed this part. I'm talking about the max press in 2E PHB from when I was a kid.