Really, the class with the "wrong" name is wizard. Even without the etymology, it carries the connotations of "wise person" - here comes the wizard, Gandalf the Wise. Originally, this class was called Magic User and wasn't renamed Wizard until 2nd edition. It was inspired by renascence figures like Doctor John Dee, who applied the developing modern scientific method to the study of magic, before people discovered magic wasn't real. Hence the dependence on intelligence (book smarts) rather than wisdom (insight). If these people where known as anything, it was Cunning Men or Sorcerers, never Wizards.
So, if you really want to be pedantic about class names, I suggest renaming wizards to sorcerers, druids to wizards, and sorcerers to mutants.
Of course, there would be a lot less confusion if you leave the names as they are, but remember that they are just labels for a set of mechanics. How they are known within your fantasy world can be whatever best fits your setting.