D&D has always had mage spells and cleric spells (arcane and divine). From 3rd edition on, the spells have been grouped together, but there are still spells only a mage can cast and spells only a cleric can cast. And in 1st and 2nd edition, all spells were separated. Not only that, a cleric version of one spell could have completely different ranges, durations, and so on, then the same mage spell.
Just not sure of your point.