Here's a clue:
Jesus personally picked ALL of the real Apostles...Jesus did not pick THAT apostle...
Guess what that means...
There are 12 Apostles mentioned in the book of Rev...Guess what that means...
Hmmmmm...guess? That's a good word to use. Your guess is as good as mine. :-) If the Apostles were chosen by the Savior and they were inspired men, and they felt inspired to ensure there were 12 Apostles to lead the church, and they felt inspired to choose Matthias to replace Judas, then succession makes sense.