Note: you must not delete or rename the Default typography!

The key questions that help you to know how many typographies you need, are:

•The publisher produces one print product only?

If so, you can use the Default typography for all your formats.

•The publisher produce more print products using the independent GN4 databases?

If so, you can use the Default typography for all your formats.

•The publisher produce more print products using the same GN4 database with a clear separation of all products?

This means: although there is only one GN4 database, the print products need to be independent and the formatting of one product must not clutter the workspace of other products. If so, you can use the Default typography for the formats of the first product, and then create new typographies for other products. If some formats need to be available in more print products, you need to duplicate them.

•The publisher produce more print products using the same GN4 database with sharing formatting between all products?

If so, you can use the Default typography for all your formats.

•The publisher produce more print products using the same GN4 database with sharing formatting between some products?

If so, you can use the Default typography for all your formats of the products that share formatting, and then create new typographies for other products.

•The publisher produce more print products using the same GN4 database with sharing some formatting between some products and other formatting needs to be independent?

This is not really supported. If the titles (products) use the same typography, then ALL the formatting is "shared". If the titles (products) use different typographies, then NON formatting is "shared".