text: Actually, it is the pros who accept oral tradition as reliable source, in African history, American Native history (also US and Canadian courts), Chinese history, just to name a few.  You are a tad bit behind ... the pros. 
  
  Re the Latin Prologues, the current scholarship is divided. So, you cannot simply dismiss it it based on that. 
  
  When looking at all the evidence together, and especially the living tradition, that includes the continuous veneration involving the Martytium in Alexandria (originating prior to 313, which means no ulterior motives were desirable), you can argue as much as you want it won't help. :))
  
  BTW< my original comment was that Christianity in Alexandria (Egypt), and among the Copts is not "centuries" old, but millennia old. 
  
  You can carry on with your nitpicking, argument for argument's sake, if that makes you happy. :)) Coptic Christian community is still one of the most ancient in history. :)) Have fun with the pros! :))