We have the older spellcaster, the psion, who's been in this game since before I was born, and bring it to the modern edition. Like, at least the Warlord I get people don't like it because its a 4E thing. Psionics have been "This is distinct from wizardly magic" in this game since 1978. They're not Arcane spells. They're psionic spells, and this has been defined this way for over 40 years.
And Aberrant Minds cast psionic spells. The psion (whether 2e, 3.0, or 3.5, so 33 years not 40) looked like a wizard, talked like a wizard, had hit points and spell slots like a wizard, and wore armour and used weapons like a wizard. And cast spells almost entirely like a wizard ... other than from a different list that was frequently full of things like "Charm, Psionic". And the only substantial differences were:
- They used a "manifester level" not a caster level
- They used a display not components
- They used power points not spell slots - and could occasionally be upcast
This is as much a lazy knockoff of the wizard as the 3.0/3.5 sorcerer was. The key difference between the two being that Sorcerers were added as an excuse to give wizards more spells because they "shared" them, while Psions didn't share the word because it allowed you to add spells like Darkvision, Psionic, and fill column inches to sell more books full of crunch.
In 1e psychic powers were at least different to magic spells - so 40 years isn't true. They were just very bad mechanics.
And, yeah, y'know what? Wizards should lose a lot of spells. They should get an identity that isn't just "Grab bag of spells in the game"
Wizards and sorcerers
do have an identity that isn't just "Grab bag of spells in the game". Admittedly it took about a decade for sorcerers to get one. (4e as ever delivering the fluff). But wizards casting their spells out of books allows them to change up their spells in a limited way and to cast rituals without having them prepared.
But if we're talking about identities in mean terms
Psions need one beyond "Power point casters" (Aberrant Minds are) who use psychic spells (Aberrant minds do), have no V,S, M components (again Aberrant Minds do) and are an excuse to print and sell you new spells and reprint spells with a splash of paint such as Grease, Psionic. Aberrant minds cover the
entire mechanical identity of Psions that's not a naked cash grab to sell more books and bloatware.
Extrapolating this, all magic being the same, implies that divine magic is just the same again.
Divine magic
is just spells. It's just a different spell list.
But there are significant differences beyond that between a
Cleric and a
Sorcerer. A cleric traditionally stands in the front lines, wearing heavy armour, bashing people over the head with maces, and can change up their spells on a daily basis. Even when we make the Sorcerer a Divine Soul Sorcerer so their spell lists thoroughly overlap it's generally possible at a glance to tell the metamagicking Divine Soul from the beefy and armoured cleric.
Meanwhile there is minimal difference between a sorcerer and a psion.
Both stand in the back lines with the lowest possible hit dice, wear no armour by default, and are about as inept with weapons as it is possible for a playable class in D&D to be. They hang around in the same place at the battlefield, wearing the same clothes, using the same weapons, and doing the same things (casting backline spells) that refresh on the same daily cycle with many of them having almost the same name, such as Banishment and its knock-off Banishment, Psionic. Both can upcast and neither of them can readily change up their spells the way a cleric or wizard can.
This means that when we open up the more psionic spells to the sorcerer and give them the tiny pieces of fluff of no components and of outright power points there is
nothing left of the active identity of the Psion. They walk alike, dress alike, cast alike, cast the same spells, and can change their spells in the same way and on the same cycle.
I'm grabbing your argument and applying it to an identical case but another class that, let's be honest, has less differences in the game's history than the differences between psionic spells and wizard spells. Its a perfectly applicable argument, especially because cleric spells and wizard spells are structured the same, and at least psionic ones have been structured differently in the past. I absolutely don't want to look at any of those old structurings (3.5E and 4E psionics should be the go-to), but its a well established thing.
4e psionics were annoying. As a 4e fan psions were one of the things I don't want to see - and although I'd like to see a redone Battlemind it takes working from scratch.
See, this is the thing. "Its magic therefore its wizard stuff". Guess what else is magic? Cleric spells. You want to merge those in as well?
Divine Soul Sorcerer already has them. They don't have all cleric spells and all psychic spells
at the same time. But they have them and it doesn't threaten the cleric.
"Its magic therefore its just a wizard" hits the cleric exactly as much as it hits the psion.
But the cleric is wearing heavy armour, carrying a shield, and has a d8 hit die. Meanwhile the psion has the same hit die as the wizard (or sorcerer), and is wearing robes like the wizard and wandering around the back lines like a wizard. The basic
attack might be the same - but gets stopped by the cleric's (literal) armour. The psion is making death saves.
And psionics is another source. If clerics are safe from the 'merge into wizard' bat due to the different source, then so are psions.
It's not
source that keeps clerics safe. And it's not "merging into wizard", it's "Merging into sorcerer". As mentioned you can and they have merged the entire cleric spell list into Divine Soul Sorcerer and it does not threaten the cleric class because a cleric does not behave like a wizard or sorcerer.