In ACTS: 1; The writings of Luke inform us, that Peter brings to the attention of the eleven remaining Apostles including himself, as well as about one hundred and twenty Disciples with them in the upper room, that there was a need to replace Judas Iscariot who was a member of the original 12 Apostles. Peter correlates his decision with the Twelve leaders of the Twelve Tribes of Israel. Peter sites the writing in the Book of Psalms; “Let his habitation be desolate and let no man dwell therein and his bishopric let another take.”
Peter sets the parameter for choosing stating that the candidate must have been present at the Baptism of Jesus up to and including the ordination of the remaining eleven and their witnessing of the resurrection of Christ Jesus. After much deliberation, and a drawing of lots, a Disciple named Matthias was chosen to complete the group of twelve.
Peter believes that what became known as the “Circle of Twelve” was now completed, but as usual, he did not consult with God or Jesus, for not too much time passes and Jesus himself selects a twelfth Apostle when he converts and recruits a man on the road to Damascus named Saul, a man who had been persecuting Jesus followers and Apostles and killing them.
Saul, renamed Paul, becomes the thirteenth Apostle, the Apostle to the Gentiles travelling throughout areas like Italy and Greece teaching the Holy teachings of Jesus, building new churches, recruiting thousands of Christians, helping to establish the Christian Church and its dogmatic policies teachings and practices in the name of Jesus.
More than 2/3rds of the “New Testament” of the Holy Bible can be attributed to the Apostle Paul.
Who else but Peter would try to second guess Jesus concerning the “Group of Twelve”?