There are several types of intelligence in the real life. You can be good for a thing but bad for other. For example using fictional characters, Stever Urkel from the sitcom Family Matters would be high Int but low Cha and Wis. The characters from "Big Bang Theory" are very high Int, but low Cha. Katarine Claes, the main character from "my next life as a villainess" is oficially the dumbest one, but... she is too charismatic and everybody loves her (because she is very friendly, and generous with the compliments.
Wall-E and EVE almost didn't talk, but they could communicate their feelings. There are more example of cartoons characters who couldn't talk, but they were moving.
Sgt. Hartman from the movie "the metalic jacket" is an example of low charisma. Clint Eastwood's character, the sgt Thomas Highway in "Heartbreak Ridge" is very unfriendly, almost as much as Sgt Hartman, but he was high Charism.
You couldn't watch Darth Vader's face but you didn't want to make him to get angry. Grogu, alias "baby Yoda", is one of the most loved and popular characters from the last years. The famous Pikachu, or Groot, only with a word/phrase, but very loved and popular.
I don't see Cha as "willpower" but the talent to earn the trust or linking by the rest.
Omni-Man(Nolan Grayson), the father of Invencible(Image Comics) and Doomdays(DC) could be the same willpower, but Omni-Man is more charismatic than Doomday.
In Disney's Encanto, the mc, Maribel Madrigal, isn't so pretty as her sister Isabel or her cousin Dolores, but she is most charismatic and with hight number of possibilities to become the new matriarch. Her cousin Camilo is very funny and friendly, but he hasn't the true charisma to be a leader.