Whose word do we have that Christ intended us to follow Paul? Paul’s.
We have many dozens of instances within the Synoptic Gospels that Jesus called people to follow him. It is later confirmed in both the Letters of Paul and 1 Peter 2:21. When Paul tells others to follow his Gospel, he is not claiming the authorship of the Gospel he is telling people to follow the Gospel that he (Paul) is preaching which is the Gospel of Jesus.
St. Paul is not the loon, it is those who have twisted his teachings into the mantra of a self-centered heretical cult who are the loons, crackpots, mentally unbalanced, and their dupes.