If you name your site after yourself to get more approval from the big search engine, then someone has a good guess at half your login. WP allows for the displayed name to be different from the username. I don't know why anyone would give anything away --security-wise-- that they don't have to.

Pick an obscure word for an original username and then display your first name or nom de keyboard to the public side. Isn't that sorta like adding a factor in itself, or at least restoring one that you already could have without added rigamarole?

Just yesterday I had someone try to break in using my first name, although commonly they try "admin", which was another example of over-sanguinity about security on the part of WP.