Why did St. Jerome place Peter's letters after James's letter if Peter was the leader of the apostles and the church?

The Catholic Church believes Peter to be the leader of the apostles. Also, by the time that [Pope Damasus I commissioned St. Jerome](https://en.wikipedia.org/wiki/Books_of_the_Vulgate) with the Latin Vulgate translation of the Bible (AD 382), the papacy was already firmly established. Why then St. Jerome placed the letters of St. Peter *after* James's letter among the catholic epistles (implying that James's letter is more important Peter's letters), not to mention placing the whole group of Paul's letters before the catholic epistles? Please note that I'm not making the assumption that order automatically implies importance (whether of the subject matter or of the author). For example, the reason why Matthew came before John was that the early church (including St. Augustine) [believed that the canonical order follows the order in which the 4 gospels were written](https://taylormarshall.com/2011/09/why-matthew-is-first-gospel-and-not.html) . Did the same reason apply to the ordering of the catholic epistles? **My question**: In the (presumed) absence of other deliberate ordering reason, why is it that James's letter was placed before Peter's letters among the catholic epistles?