Hypothetically, if D&D had to reduce the number of classes, and they where going to remove the ones that has the least identity, which ones would go?
Presume the options to play the character would still be in the game somewhere, just not as a class.
I.e. Fighter gets moved under Ranger, Wizard is a Sorcerer option, ect...
Hmmm. As of this post, the fighter, ranger, sorcerer and wizard are the only classes in double digits. Makes sense. The sorcerer and wizard are essentially slightly different stories and mechanics stapled to the same general archetype, the ranger is a cool story with no mechanical niche, and the fighter is a generic blob of swords.
Ranger being aberrant for lacking good mechanical identity, I think the problem with fighter and wizard/sorcerer is that they are too generic. They are trying to be a dozen different things each. Fighters have to be knights, swordmen, gishes, samurai, supernatural warriors and Jedi in 5 class features. On the other hand, the wizard encompasses diviners, necromancers, elementalist, summoners, enchanters, witches, demonologists, and every other arcane magic caster under the sun and the sorcerer gets to do the same things backwards, in high heels, and with crappier spell lists.
Here's a suggestion, kill wizard, sorcerer and fighter and replace them with more specific classes. Fighter could be a knight/cavalier, a warlord/commander and a gish/magic knight. The sorcerer/wizard should become a dedicated beguiler, summoner, Necromancer and elementalist classes. Then you give transmutation to the artificer and ranged/skirmisher to ranger. Every class has a story, every class has unique mechanics, and no generic I hit things/I cast spells classes.