If you have one physical disk, you have one location.
It is irrelevant how many copies of various files you maintain on it.
It is also irrelevant whether you choice a storage filesystem that duplicates things for you or whether you manually maintain copies.
Consider the scenario of what happens when your disk fails.
When that fails you lose everything.
You may need to review how important your files are to your business, your clients, your reputation.
Balance that against the choice to "do things on the cheap".