They most likely are written documents derived from earlier oral traditions that arose shortly after the Resurrection..
The Two Source Theory has the advantage of parsimony, as compared to the "it is possible" contortions of the present writer.
Where do you come up with this rot? Especially during Passion Week. Do you two deny the Crucifixion of Jesus Christ? Do you two deny Christ's Resurrrection.
Or are you cherry-pickers?