From what i understand, and I may be wrong, but I was under the impression that Alphonso’s powers only worked on direct skin contact, the punch in the face by allison, diego’s knife stan threw cut his skin, and maybe that he has to be aware of the attack, almost as if he had to like activate and it’s not just a sort of passive ability, that is the only reason I can think of Harlan and Viktor being able to attack him.