You know what would be funny? If Nezuko's sunlight immunity was directly tied to her never eating a human. So even if Muzan DID capture her, he STILL wasn't able to make himself immune.
He couldn't find him? The eyeball swarms seems to be a NEW power of lute demon's. And that's how he located everyone.
So which is it? Do you want them to attack non-stop so he can't regenerate, or not?
Depends how long the arc is. Muzan + 3 Uppers vs.the entire Slayer Corps. is some "4th Ninja War" shit. Imagine trying to do that arc in 1 movie.