I believe you have to nominate all your attacks att the same time, and therefore there is now certain order in which the attacks are actually made. For example, if you have 2A and fight in a combat with 2 enemies, where one is knocked down, you can't first role 1 dice to see if you managed to get the standing warrior, and save the last dice in case you didn't succeed in injuring him.
So somehow I say that you should be allowed to parry the other attacks, since the attack (6) that was put away buy the lucky charm is not a threat anymore. Though I agree it is a picky situation.
– popmouth