Never stated that normal luffy>>nightmare luffyYeah, except Luffy couldn't toss around Oz like that either. You have to realize Nightmare Luffy equals Luffy+the power of a hundred shadows.
Luffy can't be>Luffy+the power of a hundred shadows, that math doesn't add up.
Nightmare Luffy>Luffy.
Moriah lost to Gear 3+Gear 2 Luffy, who is weaker than N. Luffy and Vergo, so Vergo would beat him too. Superior speed plus his monstrous hits would be too much for Moriah.
It doesn't matter if you think Nightmare Luffy<Normal Luffy because Vergo is still stronger than pre-skip Luffy anyways.
Normal luffy couldn't beat Moria
Gear 3 luffy was strong enough to K.O a giant and break Oz.
Nightmare luffy thrashed Oz, not break him.
So gear 3 is able to do that, with the addition gear 2 it takes his gear 3 strength one step higher.
Vergo is not beating that luffy.
May I remind you that you are comparing post timeskip Vergo to pre timeskip Moria?
Excluding that, Pre timeskip luffy also fought the Boa Sisters who have observation and armor Haki (well at least one of them does).
He overpowered their armors Haki with brute strength, same thing happened in the colleseum when the funk brothers when they overpowered that happo navy Haki.
Or the boxer with explosive power matching another happo navy's Haki with brute strength.
So gear 2 (marineford) luffy would may lose to luffy (maybe), but gear 2+3 luffy is beating Vergo off pure brute strength