Here is list of reasons why Paul is far more likely to have been God's replacement than Matthias.
"Factors Which Question the Actions of the Apostles
(1) The action taken was prior to Pentecost, before the Holy Spirit had come upon the apostles to guide them.
(2) The apostles were “taking action” when Jesus had specifically commanded them to wait, until the Spirit had come on them.
(3) Jesus had chosen all of the other apostles (cf. 1:2), and He had given them no command to choose a replacement for Judas.
(4) While there is a minimal reference to “the twelve” later on, Matthias is never again specifically referred to in the New Testament. Why is so much attention giving to the choice of a man who is then ignored throughout the rest of the New Testament?
(5) The context surrounding this incident does not suggest that it was a decision prompted by a command of the Lord, a biblical imperative, or the guidance of the Spirit. I have mentally labeled this section, “Doing What Comes Naturally.” It seems that the apostles were, along with the rest, acting on their own, apart from any clear imperative or command. In the immediate context, the disciples seem preoccupied, and Jesus had to turn their attention toward things other than what they had in mind. The angels had to spur the group on, rather than to stand on the mount, looking into the sky. The immediately preceding context suggests that the apostles still had things out of focus, while the immediately following context (Pentecost) informs us that the Spirit’s coming was not yet, and thus suggests that the apostles were acting on their own initiative, and not that of God.
(6) The motivation of the apostles might seem suspect, when considered in light of their past thinking and actions. You will recall from the Gospel accounts that the disciples were eager for the kingdom to come, but from a motivation of self-interest, from a desire for position, power, and prestige. They were even competitive with one another. Why then the urgency for the position of the twelfth apostle to be filled? It could be suggested that it was because the disciples felt the kingdom could not come until there were twelve apostles in place, so that there would be twelve thrones filled in order that the twelve tribes could be judged. This would be a reasonable conclusion, based upon our Lord’s words to the disciples in Luke 22:30, spoken shortly before His betrayal, arrest, and crucifixion.
(7) While Peter’s interpretation of the Old Testament Scriptures to which he referred may well have been sound, the inferences he drew from them are possibly more suspect. Jesus Himself linked Old Testament prophecy to His betrayal by Judas. He cited Psalm 41:9 in John 13:18 and 26. Peter seems to allude to the text in Psalm 41:9 cited by our Lord, but he specifically quoted from two passages from the Psalms. The first citation was from Psalm 69:25; the second was from Psalm 109:8. If Peter’s interpretation of these two texts as being prophetic is correct, I am not certain his interpretation necessarily follows from them. In the first citation from Psalm 69, the text Peter cited is this, “LET HIS HOMESTEAD BE MADE DESOLATE, AND LET NO MAN DWELL IN IT.”
(8) Now from the account of the fate of Judas, which Luke has given to us parenthetically in verses 18 and 19, who was it that made the homestead of Judas desolate? It was surely not the disciples nor was it anyone else who consciously did what they did in order to obey this prophecy. God fulfilled this prophecy. And so, when we come to the second statement, “HIS OFFICE LET ANOTHER MAN TAKE,” should we assume that there is anything called for here on the part of the apostles? I think not. If God fulfilled the first “LET …” from Psalm 69, why should the disciples feel obliged to fulfill the second “LET …” from Psalm 109? If the second citation were fulfilled in the same way the first was fulfilled, the disciples would not need to have done anything. I am not certain the Old Testament text requires anything of the disciples, but Peter and the others felt it did.
(9) The process used to choose Judas’ replacement seems somewhat suspect. At best, one can say that the selection of Matthias was carried out in an Old Testament fashion by the casting of lots. This method was never given to the disciples, nor is it ever found again in the New Testament as a means of determining who God has chosen to hold any office. The casting of lots allowed for a decision to be reached totally apart from divine intervention. Of course God can and does determine the outcome of the casting of lots (Proverbs 16:33), but is this the way God intended this decision to be made? The candidates were nominated, and the two candidates put before the Lord were chosen by the group, based on the requirements they themselves determined. They allowed God to choose between the two candidates. Somehow this seems sub-standard to me. The method employed by the group seems to put God in a box and to limit Him to the options men have placed before Him.
(10) Luke’s argument in Acts seems to challenge this action, because in Acts Paul’s apostleship seems to be affirmed at the expense of that of Matthias. Paul constantly stressed that his apostleship was the sovereign will and purpose of God, and not of man. He also spoke of himself as an equal with the rest of the apostles.3 And remember, Paul was also a witness of the resurrection of Christ, for he was stopped short by a vision of the Lord Himself, risen from the dead. If Paul’s apostleship is affirmed and Matthias’s apostleship is ignored, there is good reason to question the legitimacy of Matthias’ apostleship. There is at least some evidence to challenge the action taken by the apostles due to this emphasis on Paul’s apostleship."
