Login Name as Alternative to Username

Question

Noticed MSN account was getting multiple sign in attempts a day from IP addresses in Russia or Africa. Realizing it had become a target, I could assign phone number as primary login. And remove login via email address.Thinking about making this a generic security practice. For all accounts with public facing usernames.Is this something talked about in security circles? I have to go through workarounds to make this possible for certain accounts. So this is not easy.

onlinejk · Accepted Answer

To clarify, am I right to interpret this:
* "I could assign phone number as primary login"
... as equal to this:
* Change old login value (wasabi@weasel.tv) to new login value (3035551212)
?
If so, personally I wouldn't like that most of my usernames were going to be same. I realize different usernames is security through obscurity at best, but that is my initial reaction.