Validar did the same to Aversa, I'd change up the tutelage under Validar, also Bearing the crest of the Mad King wouldn't exactly be the smartest of ideas he may want to save that for when people get to know him better. Like how Virion hid his nobility. Also if Validar thought he would be useful he would have given attention to the young prince as he would either be a unifying puppet for Plegia, thus using him as he did Gangrel, or killing him outright.

Welp silly me you already figured everything out.