Arlong & Jinbe weren't the first ones to name Jinbe, that was Yosaku, and if I recall correctly Jinbe wasn't really named afterwards.
Also some stuff you're talking about, like destryoing Kaido's weapon factory or Gedatsu landing in Alabasta, isn't stuff you can count in that sense. This is stuff that happened in the cover story itself. That isn't knowledge/things we know/etc. that were there before the cover story.
And as I already mentioned, a Brownbeard/kids CS wouldn't work, because we already know the outcome => they're coming home/into prison.
And that we nevere really saw what happend to the YCB is the whole point, why some of us actually would like one. Why not have one panel showing them? That they were defeated isn't a reason for them to not come back, since most villains were beforehand. For Shinokuni, they could have woken up in time (there was quite some time between defeating them and letting Shinokuni loose) or something else could have happened, Oda just needs to be creative.
Most cover stories probably are there, because Oda has new ideas for some characters - which we don't know right now (e.g. Jango, Hatchan) - or just to have a little, fun side adventure (e.g. Gedatsu, Ace).