Can we now surmise that the 80% that have no remarkable symptoms could be it’s Trojan horse?
Sadly, '80% have no remarkable symptoms' isn't true. I outlined this in more detail a few threads back, but that 80% splits roughtly 50/50 into mild and moderate disease. Moderate disease is defined as pneumonia, but not needing hospital admission.
Under normal circumstances, the average man on the clapham omnibus would not consider pneumonia as a mild cold, or nothing to worry about.
My source for this are pages 12 and 13 of the WHO report that came out a week or so ago, and I think is linked in the OP.