So we're going to be using the old "Well _blank_ beat _blank_ once, so he wins here der der der!!!!!1!"
Cena as a submissions "expert" is fucking laughable. He knows one submission move, maybe two. Kayfabe or not, that isn't expert. At all. Get the fuck off of the man's dick, my goodness.
It is a kayfabe tournament. As in, it's fake. As in, what other type of criteria do we have to judge them other than by the people they have defeated?
If Cena has defeated the likes of Triple H, Shawn Michaels, Benoit, Jericho, Edge, Orton, Khali, and Umaga with his submission maneuver, how is he not a submission expert? He has taken down legendary men with his STF. The expertise in this example isn't in knowing a lot of submissions, but rather he knows one that he uses to great effect.
I'm not on the man's dick. I'm arguing from a kayfabe point of view that you seem to have lost in between hating on Cena and some how enjoying Mysterio.