I dont remember the dragon saying that he got it from a hero, it could have been from a knight that fought in the great war, which is possible that hylia sent the knights up to Skyloft. Again the red bird still could represent a crimson loftwing. because the knights could have had the loftwings during the war pre-skyloft.
Well it is also possible it was a knight that fought in the great war before Hylia sent them up to Skyloft. Which mean that the nights still rode on Loftwings. Due to the red bird on the shield.You definitely have something going on in here, if the hero before Link defeated Demise with that shield, it would make sense that t was given to the dragon for the next hero, although this kind of conflicts with my theory of Link being the original hero, it would also make the name have sense,Hylian shield