Class Power Source

[Jaeda]

I think that Ardent and Battlemind are both supposed to be fantasy Jedi, but the in-universe distinction between the two is kind of fuzzy to me, and I'll concede not really being able to come up with much else that either class really models.

This feels like one of those cases where maybe they should have been one class with a subclass that then determines their role, or maybe having a common set of powers shared between multiple classes with the same power source. This is sort of the flip side of a few classes where it feels like they fill different archetypes in different roles. Examples include sword-and-board (defender) vs greatweapon (striker) warriors, evoker/battlemage (striker) vs enchanter/illusionist (controller) vs abjurer (leader) wizards, bear (defender) vs cat (striker) vs caster (leader or controller) druids. A conjurer could conceivably fill any of the roles depending on which kind of creature is summoned but would probably fit most cleanly as either a striker or defender based on the kind of creature summoned (subclass) with a leader secondary from the caster themself.

[Kurald Galain]

I think that Ardent and Battlemind are both supposed to be fantasy Jedi,

Sure, but so is the Swordmage.

[RedMage125]

I think that Ardent and Battlemind are both supposed to be fantasy Jedi, but the in-universe distinction between the two is kind of fuzzy to me, and I'll concede not really being able to come up with much else that either class really models.

As I recall, Battlemind is one who manifests psionic powers through their body, like the Psychometabolism discipline of editions past.
Ardents, and this I do remember, manifest their psionic ability through emotion, not thought or will.

This feels like one of those cases where maybe they should have been one class with a subclass that then determines their role, or maybe having a common set of powers shared between multiple classes with the same power source. This is sort of the flip side of a few classes where it feels like they fill different archetypes in different roles. Examples include sword-and-board (defender) vs greatweapon (striker) warriors, evoker/battlemage (striker) vs enchanter/illusionist (controller) vs abjurer (leader) wizards, bear (defender) vs cat (striker) vs caster (leader or controller) druids. A conjurer could conceivably fill any of the roles depending on which kind of creature is summoned but would probably fit most cleanly as either a striker or defender based on the kind of creature summoned (subclass) with a leader secondary from the caster themself.

Some of your examples, yes. A greatweapon Fighter as a Striker is why Essentials gave us the Slayer, which is one of only 2 Strikers that wear Heavy Armor (Blackguard being the other). Most Heavy Armor wearing individuals are Defenders, Leaders, or Controllers.
Disagree on all your Wizard examples. A Controller has 2 functions: 1) Battlefield Control (through terrain modification and inflicting status effects) ans 2) AoE damage. So your Evoker and Abjurer are still controllers, especially because Leaders buff allies and heal them, which Abjurers do not do.
Your druid examples, especially separating bear and cat, seem too much inspired by WoW. But I could see an argument for Leader for the druid, and MAYBE Striker, for the focus on Wild Shape.