In my experience the debate about "what is a unit" is a waste of time.
What matters far more is "how fast is the test?" Fast tests run at the rate of 100+/second. Slow tests run slow enough that you don't reflexively run them every time you pause to think.
If your tests are slow you won't run them as frequently, making the time between bug injection and bug detection longer.
If your tests are slow you probably aren't getting the design benefits of unit testing.
Want fast tests? Follow Michael Feather's rules of unit testing.
But if your tests are fast and they're helping you write your code, who cares what label they have?
