Xanathar's Guide to Everything greatly expands on the use of tools. Here are parts of the section on Cobbler's Tools (p. 80):
Although the cobbler’s trade might seem too humble for an adventurer, a good pair of boots will see a character across rugged wilderness and through deadly dungeons.
Components. Cobbler's tools consist of a hammer, an awl, a knife, a shoe stand, a cutter, spare leather, and thread.
Maintain Shoes. As part of a long rest, you can repair your companions' shoes. For the next 24 hours, up to six creatures of your choice who wear shoes you worked on can travel up to 10 hours a day without making saving throws to avoid exhaustion.
The book also expands on crafting an item as a downtime activity, and its requirements (p. 128):
A character needs to be proficient with the tools needed to craft an item and have access to the appropriate equipment.
If you are proficient in Cobbler's Tools, can its benefits (making both non-magical and magical shoes, maintaining shoes, etc.) also apply to Horseshoes? Or are shoes and horseshoes too different from one another?