The key emphasis here being that The Gospel of Marcion is possibly the earliest gospel. The wiki article you link to clearly says that is a minority view not in line with early church tradition.
The earliest reference to the four canonical gospel comes from Irenaeus, who also references the at that time decades old Gospel of Marcion. The early church is not a reliable source about this, because it's strongly against Marcion.
legulere|2 years ago