Henadic Theologian
Legend
This is more a theoretical "what-if" than an actual desire to change either of these classes. But with having both the Warlock and Sorcerer (and Bard...) currently using Charisma as their prime casting requirement, what sort of effect on play would there be if we switched one (or both) off using Charisma as their casting ability?
In the case of Warlocks, what if Wisdom was their primary casting ability? Where Clerics are driven by their unshakable faith (Will) in a god, the Warlock instead is the master of "common sense" in understanding the contract between them and a supernatural entity - not the letter of the law (which would be Int), but the intent and ways to manipulate it to their benefit. The warlock knows the ins and outs of how to manipulate that "binding oath" between the two to drawn on magical power for their own use. There might be some secondary knock-on effects of "faith in the contract" or the patron, but likely not to the level of a cleric. What knock-on game effects would this have on mechanics and play? What sort of story side elements could be brought in on this?
As for Sorcerers, what if Constitution became their primary casting ability? As vessels and conduits of innate magic, the strength of their body (their vessel) directly relates to their ability to draw on and harness magical power and wield it without burning themselves out. As above, what effects would this have on mechanics and story for the Sorcerer?
In the Sorcerer's case, I think one minor side effect might be that multiclassing Barbarian/Sorcerer might be more appealing and to some degree fitting story elements of the mixing of the two.
You can do a Wis Warlock as long as you don't multiclass.
Pick say Acolyte background for Guiding Bolt, and a couple of attack cantrips and pick Wisdom as your casting stat for them. You can fire off wisdom based spells using your Warlock slots. Then as you level pick mostly spells that are summons or utility from the Warlock class where possible. Pick Chain Pact for your first Invocation. Use your wisdom spells from feats for offense along with Summon X Spells.