It is interesting that you will find they are always divided into three groups of four, with Philip always appearing in the fifth position, and James, son of Alphaeus, always listed in the ninth. The first group of four consisted of Peter, Andrew, James, and John. The second group of four consisted of Philip, Bartholomew, Matthew, and Thomas. And the third group of four consisted of James, the son of Alphaeus, Thaddaeus, Simon, and Judas.
There is some irony in the position held by Thomas in these four lists. He is listed seventh, eighth, eighth, and sixth. His "highest rating" is in the Book of Acts, which is, of course, after his infamous refusal to take the word of the other disciples that they had been visited by the Resurrected Lord (Jn. 20:19-25). And although he has been nicknamed "Doubting Thomas" ever since, Luke "promoted him" to number six!
Perhaps Luke chose to "look at his whole body of work," rather than at the one instance where he doubted. Thomas appears to have been very courageous in his response to Jesus saying He was going to Jerusalem, a statement to which "His disciples say unto him, Master, the Jews of late sought to stone Thee; and goest Thou thither again?" (Jn. 11:8). "Then said Thomas, which is called Didymus, unto his fellow disciples, Let us also go, that we may die with Him" (Jn. 11:16). However, like the rest of the disciples, Thomas went into hiding following the arrest of Jesus (Mt. 26:56; Mk. 14:50-51).
And it was Thomas who humbled himself by asking the question, "Lord, we know not whither Thou goest; and how can we know the way?" when Jesus had said He was going to prepare a place for them (Jn. 14:1-5). His question resulted in Jesus making one of the most important statements found in the entire Bible: "Jesus saith unto him, I am The Way, The Truth, and The Life: no man cometh unto the Father, but by Me" (Jn. 14:6).
How would you like to be remembered for your failure, rather than for your faith?