Hi Alex,
I would have two answers here. (Is texture the surface or the image? Hence the two files.)
File 01 shows that a single texture is used for the two caps and the main area of the Cylinder. This means they share the space of a single texture, and that requires that there are no overlaps (if the texture should be unique in each of the three areas).
In file 11, the UV overlaps, as the shared UV tag will have no conflict based on the three materials with three different Selection Tags. Each of the three materials will use a different texture and uses the most area of the texture. (Mostly, means here a circle would use roughly 3/4 of it.)
Is this answering your question?
File
https://www.amazon.com/clouddrive/share/Lg41uUzPoP5RED4Fsgb5iMQNHci7f7zXuJYepqc2YyN
All the best