How Do You Know When to Split Skills in Fate Core?

In the Skills section of the Fate Core book, they keep talking about when to split up a skill into several skills, like splitting Fight into Weapons and Fists, or splitting Crafts into Biotechnology, Engineering, etc., or splitting Lore into Arcana and Academics, and so on. Every time, though, they caution not to do it if it's just going to be "pedantic."

So, how do you know when it's appropriate to split skills and when it's just being pedantic?

Does it matter for your game? Unless you can make a compelling argument, than the answer is always no (large lists of important skills are problematic when you can only have a few, besides the mental load of trying to track them all).

One way to answer that: does it make sense for different characters to be cool by having both of the skills? If being the Most Learned Woman In The World (Academics +4) is as fun in your game as Pointy-Hatted Wizard (Arcana +4), then by all means split. In most games this won't be true (are characters really solving problems by means of Academics?). And in many cases, you can get by without splitting by using aspects (Most Learned Woman In The World).