I've never worried about the "number" of a string - to me, the G string is...the G string. Except when I tune a bass to D standard, when it's the F string. When I get a pack of strings with or without numbers, I've always been able to tell which string is which.
So, rather than worrying about what number a string is, I choose to avoid the issue, since I don't see that it is an issue.
This method is a bit silly for any tuning in which two or more strings are tuned to the same note. Although I guess at a certain point, you just point and say "this string right here."

It never even crossed my mind to worry about this. Maybe it's because I almost never change strings 