Why is Galatians placed where it is in the New Testament if it is so introductory?
Galatians is placed after the two letters to Corinthians because it has a divine purpose for that exact position, even though it is introductory and appears to belong before Romans. The Holy Spirit established the order of Paul's letters, and that order remains consistent in every available New Testament copy.
Les explains that Paul's letters always appear in the same order in every copy of the New Testament found in libraries and museums, while other New Testament books can vary in order. He notes that Galatians should logically precede Romans, comparing Galatians to an artist's pencil drawing and Romans to the final oil painting, because Galatians is introductory and does not delve into the deep things of Romans. Yet Galatians has its divine purpose for being exactly where it is, following the two letters to Corinthians.