It's not fucking overkill. There's no such thing.
I'm really disappointed with the video. That dude usually knows his shit, but he's way off the mark here. It's just plain wrong.
Getting a smaller charger might save a few hundred, but it will also increase your chances of burning the house down. Good fucking advise, huh.
Fuck that. You'll always want to charge as fast as your main circuit breaker will allow.