Yall need to chill on the Yamato hate for a while. She literally only has like 8 "face" panels. In 2 of them she has made the generic "angry face" that Hancock has made to Rayleigh or Tashigi to Zoro/Smoker, its not just a Nami thing.
You need to wait until we see how she battles, how her seriousness ties into her expressions, how her features are better defined because she DOES have different features from Nami (hair, eyes, eyebrows, etc) but Oda DOES have a female drawing issue.
Guaranteed Oda also pictures Yamato with colors so through her colors she's going to look and feel entirely different from Nami.
And this doesn't even include attire, personality, background and fighting style. She has partial Nami face, but she isn't even remotely like Nami. Robin has partial Nami and Hancock face now, and it really doesn't detract from Robin. Nami became less unique by growing out her hair, and it still doesn't really detract from her character.
You want to talk about confusing, look at this color spread:
Here alone, it doesn't include Rebecca, Violet, Pudding or Shirahoshi, but literally everyone here (save for Perona) is EITHER a clone of Nami or Robin pretty much.
And I don't say this as an all encompassing statement, because there are plenty of moments where EACH of these characters look VERY different from Nami/Robin.
Tldr: Have an open mind about Yamato until you see more of her. I can pull examples of Nami/Robin clones where they DONT look like Nami/Robin in many cases. When Oda does the typical resting face or angry face though, they look similar, but really only in those cases.