What is the question? I’m not sure I understand.
There’s two things going on here. 1, Petrine Primacy and 2, apostolic succession.
Petrine primacy comes from the fact that he chose Peter, and that he gave Peter the Keys to the kingdom of Heaven. This is why Peter became the head of the Apostles.
What we see in Acts 1, is when Judas commits suicide, Peter says that his seat must be replaced by another. Rather than the 12 becoming 11, the 12 remain 12.
This is the point that I am trying to drive home. Peter had the authority to appoint a replacement for Judas, and the Apostles had the authority to ordain priests.
Apostolic succession talks about the succession, from Peter and the Apostles, all the way down to today. Each of the sees had their own ministry and Peter was the head of all of them. Peter could appoint men to replace a see, and the bishops could appoint their priests.
Who then, are the present day twelve ?