If two players use the same character name, the ladder list doesn’t differentiate between the two players. Our names are not unique on the ladder.
For example, I created a barbarian named BarbName. And then on a second account, I created another barbarian also named BarbName.
Then they walked out together and killed one zombie.
Now they are both on the Barbarian ladder and ranked right next to each other with an experience of 33. Since they are both named BarbName, which player is which?
This does not happen in D2 legacy because we cannot re-use names.
D2R allows the re-use of names and now duplicate names are on the ladder.