I highly disagree with their definition of different from each other. Usage together does not make the words similar. If they'd said something about words you would not find together in a sentence then I'm certain you'd get very different results.
However, even if I had meant vacuum like the cleaning tool, I would not associate it with hose naturally because I use a stick vacuum.
I guess the broader point I’m making is the same as others have said. It’s a poor measure of creativity as context is important. A word on its own doesn’t necessarily mean the same thing to you as it does to me.