I recently looked through classes from older games and I realized that I didn't entirely understand the concept behind some of the mixed classes, so could someone please clarify exactly what these are:
Battlemage (Morrowind has H. Armor + weapons as skills but in Oblivion they only have weapons)
Spellsword (What's the difference between this and Battlemage?)
Sorcerer (This is getting even more absurd)
Witchhunter (I still don't understand what this is. I know they were designed for killing mages but I feel like that's not the whole of it.)
Nightblade (I get the concept well, but what's the difference between this and Witchhunters?)
Weaponmaster (Are they dual-wielders?)
Here is my personal view
Battlemage - HA + Spells + Staff (relies on staves and scrolls more then spells)
Spellsword - Robes + spell + sword (relies on sword more, spell for back-up)
Sorcerer - HA + spells, no back-ups
Witchhunter - LA + bow
Nightblade - Assassin with magic for augmenting kills
Weaponmaster - Only a class in the Game Guide but dual-wielders basically.
Here's my take:
Battlemages are mage tanks. They are mages fit for battle. Heavy armor, high defenses, and offensive high damage magic. In Skyrim, they'll perk Heavy Armor, Destruction, Restoration, Conjuration, Alteration, and Alchemy or Enchanting.
Spellswords are warriors with magic. One hand holds a weapon, the other hand a spell. Heavy or Light Armor, Destruction, One-Handed, Restoration, Illusion, Alteration.
Sorcerers are supposed to be mages with heavily enchanted gear. Enchanting foremost, then Heavy Armor, One or Two Handed, Alchemy, Conjuration, Destruction.
Witchhunters are anti-monster/magic archers. Archery, Enchanting, Destruction, Light Armor, Alchemy, Conjuration/Illusion/Alteration.
Nightblades are rogues with magic. Stealth, One-Handed, Illusion, Alteration, Alchemy, Light Armor.
Battlemage/Spellsword - The distinction between these two differs between games but in general, both are classes that use both magic and combat skills, but the Spellsword relies on combat more (or an equal mix of magic and combat) whereas the Battlemage relies on magic more. That being said, people will give you a million different definitions for these two.
Sorcerer - Basically a mage in heavy armor. No weapon skills, unlike the above two.
Witchhunter - Basically a cross between mage and archer.
Nightblade - Differs between games, but usually refers to a cross between mage and assassin. The main distinction between this and Witchhunter is that Witchhunters use bows while Nightblades use melee weapons.
Weaponmaster - This has never been a class in any of the older games.
My view is influenced by Oblivion Classes.
Battlemage - Skilled in weapons, can wear Heavy Armor or no armor at all, focuses mainly on spells.
Spellsword - Heavy Armor warrior focused on melee combat augmented by spells.
Sorcerer - Heavy Armor mage with no skill with weapons, can Absorb spells.
Witchhunter - Light or no armor, archery, conjurations and some destruction
Nightblade - My favourite. Light Armored assassin-mage skilled in Alteration, Restoration and Destruction.