[anonporridge]

No.

You're still relying on this pool of independent miners to not defect after you initiate your attack.

Also a 6 block re-org is not unheard of and does happen naturally with the standard consensus rules on rare occasion. That's not enough to cause massive destruction of confidence. Security and confidence in your transaction's immutability has always been a continuous function of how much work has been piled on top of it, and how much energy it would take to redo that work. If you are transacting a very large amount of money, it behooves you to give it even more than 6 blocks for real confidence.