Savage kanao is mid. Kanao is cool because she is Kanao. And Kanao is kind, like Tanjiro. And a little bit quieter. Never doing anything for the sole purpose of hurting another.
I'm sorry to tell you, this but you're wrong, Tanjiro is straight, it's confirmed by the manga and the anime, it's okay if in you imagination you think he likes men but canonically tanjiro is straight, so he likes women, that's why he loves kanao and he married her.