How does Galatians compare to Romans in depth?
Galatians is introductory and does not go into the deep things of Romans. It is like an artist's pencil drawing compared to Romans as the final paint and oil on canvas. Though it should have been before Romans, it has its divine purpose after Corinthians.
Les teaches that Galatians should have been placed in front of Romans, because Galatians is like an artist's pencil drawing of what he has on his mind, while Romans is like the final paint and oil on canvas. Galatians is so introductory that it doesn't get down into the deep things of Romans, yet it has its divine purpose for being exactly where it is, following the two letters to the Corinthians. Les also notes that Paul's letters are always in the same order in every New Testament copy, suggesting the Holy Spirit laid out that format.