I'm sorry to hear about the loss of your friends
In my opinion, all of these boil down to control of movement, often trading speed of movement for accuracy of movement in a wide variety of fishing environments. This is identical to what Mark has just written:That same page can be a certain avg. distance for smooth casts. It can be a proper double hauling, getting rid of a tailing issue, positioning the rotation more efficient or many more. It can also be to get rid of pain coming in too often. Or being able to expand fishing time......It was a tough situation having had a group of six along the Swedish coast, all much older than me. Boy, did I learn about different desires in that week!
regardsa wider range of controlled motion is exactly what is needed to improve someone’s chances of getting a fish.
Vince