Measure Names isn't a real dimension, which means table calcs like INDEX() don't recognize the different Names as partition rows.
You also can't use Measure Names in a calculated field, which prevents you from doing something like IF [Measure Name]=='Blacklist' THEN 1.
If you really want row number, you could use a scaffold. I just did an example of this, including an example with row numbers here. Re: How can I automatically sort a bar chart with measure names/values?
Thanks for the reply (that Measure Names can't be used) as well as the scaffold example. It took me a while to reverse engineer what you did in your example and get it working for a test data set that I have, but I was finally able to get it running. More painful and more delicate than I would like, but since Tableau doesn't allow the Measure Names values in calculated fields I guess this will have to do.
Glad it worked for you. I apologize if I skipped a few steps in the explanation. I know how frustrating this can be, so please in the future don't hesitate to shout out if it's not obvious how to get from step 3 to step 4.
I agree it's a bit of an involved workaround for such a simple issue. Another option might be to create another worksheet with just the row numbers and put the two worksheets side-by-side, but I really don't like these solutions either. So until Measure Names becomes a "first class" dimension, I don't think there's a good solution to your problem.