Charlo gives away rounds getting lazy at times but with Castano he's going to have to work. Castano also isn't going to be able to walk him down the way he did with Teixeira either as I'd back Charlo to have the power to hurt Castano and the ability to land it if Castano isn't cautious.
Also it's a great fight as it's unification. Doesn't matter who has the belts. Putting them together is always a positive in my books.