“The Apocraphal books were never considered inspired; Jerome made that clear (but even he isn’t the final arbitrator: the Spirit didn’t allow it).”Jerome never argued this. All Jerome argued is that for these books he lacked hebrew versions. They were to be found to him, only in the Greek. They include parts of books, such as Daniel. Hence why he was less confident as to his translation matching the original.
Seems like Jerome did make himself clear.
Jerome and Origen are the only fathers considered to be true biblical scholars in the early Church, and Jerome, alone among all the fathers, is considered to be a Hebrew scholar.
His translation became known as the Latin Vulgate and became the standard Bible translation used by the Western Church throughout the medieval ages and the post-Tridentine Roman Catholic Church.
Jerome lived in Palestine and consulted with the Jews. As a result he refused to translate the Apocrypha because the books were not part of the Hebrew canon. His position was that of Rufinus and Athanasius. He made it clear that the Church of his day did not grant canonical status to the writings of the Apocrypha as being inspired. While commenting on the Wisdom of Solomon and Ecclesiasticus, Jerome made these statements about the books of Judith, Tobit and Maccabees:
"As, then, the Church reads Judith, Tobit, and the books of Maccabees, but does not admit them among the canonical Scriptures, so let it also read these two Volumes (Wisdom of Solomon and Ecclesiasticus) for the edification of the people, not to give authority to doctrines of the Church "
Jerome's convictions about the canon were clearly expressed in numerous places in his writings, in particular, the Prefaces he wrote to the Old Testament books. In these he enumerated the canonical books according to the Hebrew canon, thus rejecting the Apocrypha.
NPNF2, Vol. 6, St. Jerome, Prefaces to Jerome's Works, Proverbs, Ecclesiastes and the Song of Songs; Daniel. http://www.christiantruth.com/articles/Apocryphapart2.html
“While commenting on the Wisdom of Solomon and Ecclesiasticus, Jerome made these statements about the books of Judith, Tobit and Maccabees:
‘As, then, the Church reads Judith, Tobit, and the books of Maccabees, but does not admit them among the canonical Scriptures, so let it also read these two Volumes (Wisdom of Solomon and Ecclesiasticus) for the edification of the people, not to give authority to doctrines of the Church’ “
Where does this mention Daniel?
The Codex Vaticanus we possess, which is an older manuscript contains all these books, save Maccabbees. So clearly they were in use by the early 4th and late 3rd centuries by the Church at that time.
And yet Hebrew Canon was closed only at the anti-Christian council of Jamnia (70 AD) which was called explicitly to refute Christians who were quoting from scripture to prove that Christ really was God.