The numbers are encased in brackets, so no, not one step but several, as the brackets need to be taken into account too. However, it's moot point, since as I said, the drag and drop creates a
more complex name. At the end of a working day, I don't want to faff around with different programs to perform various tasks, which my DAW could do much quicker.
I could twist this, to follow your logic, and say, why have any naming of exported files at all? Sonar could just add a number to the exported file, and ask you to use a separate naming utility tool to name your wav files properly!
I don't think users would be happy, do you?