It's kinda like that.
"Naturally I was going to write 'the famous Austrian psychoanalyst Sigmund Freud,' but I thought of that other famous Austrian and immediately had a mental image of Hitler stroking his mustache and saying to some hapless patient, 'So . . . tell me about your mother.'" -subversivepanda, "All About My Brother: A Taiping TL"
One of the ways to use an HC born after the PoD, Historical Character In Name Only is where a character bearing the same name as their OTL equivalent is born, but they are not similar. There are several smaller variations; maybe their entire life was different, or only their personality. Either way, these HCs act out-of-character, but it's justified by the "Butterfly Effect."
This gets played a few different ways:
- Played Straight: European nobles lend themselves to this very well. If you're the fifteenth Louis to grace the throne of France, your regnal name is "Louis XV," and there's not much you can do about it. (Note, though, that European nobles tend to have names to spare, so quite possibly a different Louis XV will be Louis XV In Regnal Name Only.)
- French aristocracy tended to use their titles as last names: name any French noble, and odds are the name you thought up is actually their domain. Barring promotions, any published Baron Monthesquieu or Comte de Sade could have the same kind of name recognition, regardless of what they wrote.
- Explored: If they're born soon enough after the PoD, it's plausible that a Name-Only character would still be recognizable, but would (because of butterflies) have a markedly different career.
- Played for Laughs: More often than not, a Historic Name Only shows up as a stylistic flourish, showing that the world isn't just different, it's far gone enough to be ironically different. Hitler is especially prone to this treatment.
Contrast with In Personality Only, where only the name changes.