Maybe you are assuming too universal a corrective process. Matthew and Luke clearly knew Mark, but it is not so clear to me they knew each other or were concerned with each other. When they wrote (ca 80), there must have been living old persons who remembered Jesus and who could serve as checks against too radical a departure from common knowledge. For his part, Paul probably presupposed the Jesus tradition, as did the deutero-Paul of Ephesians 4:20-21. Still, you are on the mark about the resurrection accounts, which do expand. Meier says: "After the resurrection, the grab bag," meaning they ransacked the scriptures to find ways of speaking about an even that broke free from conventional categories. I think all gospels and letters were about enunciating risen life, since Jesus' teachings and his death are paralleled elsewhere in mare nostrum culture. And it has to be a risen life we can share.