humble minion
Legend
Pretty sure I've made something VERY similar to this thread before! Although i was more raising the possibility of making it a player choice rather than a flat-out change in casting stat.
I'd go with allowing Wis sorcerers and Int warlocks personally though. And Cha clerics. I don't really believe in Con as a casting stat.
D&D 5E - Alternate caster stats
I've never really liked how D&D puts fences around the character concepts for spellcasters, by making so much of their effectiveness dependent on a single pre-defined spellcasting ability score. Warlocks are the obvious example. Surely a quintessential warlock concept is the resentful...
www.enworld.org
I'd go with allowing Wis sorcerers and Int warlocks personally though. And Cha clerics. I don't really believe in Con as a casting stat.