If you sand “too fine” you restrict the ability of the wood to absorb the oil. It’s generally best to follow the directions, at least the first time.

Assume that the people who created the product have done the basic testing and understand how to get good results.

Then, when you have a project or two under your belt, you can start to experiment with the finishes. You’ll know how they would look if applied per instructions, and be able to tell if you like your method better or theirs.