While the marketing aspect is always relevant, there are others factors that come into play, if you look at the particular cases.
Colnago Superissmo: I've always maintained that this was the manifestation of Colnago's ego. He always believed that his bicycles were the best and he very grudgingly gave any respect to very few other Italian builders. This model was available several years prior to Campagnolo Super Record components
Tommasini Super Prestige: In this case, the model name indicates it's a higher model developed from the Prestige.
Bianchi Super Corsa: The name indicates that it was Bianchi's top road model. Similarly, Super Pista was used for Bianchi's top track model.