Just as a quick note: some display names have spaces, but they shouldn’t. I assume that there is/was some glitch that allowed users to add arbitrary space before or after their name, so I suggest trimming whitespace off all display names.
The only users whom have display names different from their actual usernames are some Twitch staff, in which case there might be multiple words separated by a space (for example, “sournothardcore” is “Sour Not Hardcore”).