Ratio schmatio. I don't believe in the ratio thing at all, and here's why:
Calcium tastes like rock or chalk, slightly metallic.
Sulfate tastes bitter to nasty bitter, depending how much is used, and thus enhances hop bitterness.
Chloride tastes like salt and enhances malt flavor just like it enhances flavor in foods.
Pick the characteristics you want, and use it, regardless of ratios. In other words, if you don't care about bitterness, it's fine to skip the sulfate altogether, and not adhere to some arbitrary 50/50 or 90/10 ratio or whatever. If you want to enhance malt flavor, use chloride. If you want to enhance bitterness, use some sulfate. If you want both, use both. If you don't care, then don't worry, you'll still make great beer.
In my opinion, chloride is great in every beer style. Sulfate is a good option mainly in either hoppy styles, or where you purposely want to jack up the minerally character and thus are forced to use something with more calcium in it, maybe even a little magnesium but go easy on that one, it's pretty nasty metallic.
I suppose I should also mention, sulfate and chloride can't be added all by themselves. They're always attached to either a calcium or magnesium or sodium. So then you need to pick which one of those you want as well. For brewing purposes, calcium works great because it lowers mash pH and has a fairly benign or even beneficial flavor characteristic.