This is the original chapter:
http://www3.mangafreak.net/Read1_One_Piece_846_4
I can see how you would make that perception but I think it's just you having a different interpretation of the scenes than how the anime team viewed it. Which is fine, but everyone interprets scenes differently given how quickly Oda rushes through some of these battles at times.
It goes without saying Luffy is worried about Nami and he does call out to her a few times in the anime as well. Maybe you feel he doesn't care as much in the anime because they show more scenes of him being tied up by the world of books and being attacked but the end result is really the same no matter how you slice it. In both scenarios Luffy was unable to do anything and was being attacked. The anime just adds to this, but the added scenes don't really change much of anything. Keep in mind that Luffy is worn out here so him not reacting immediately to those shadows is not that hard to swallow, especially given how he was confused by what the heck was going on when he was being attacked in an illusion and in the real world at the same time.
This is yet another example of how people want the manga to be a literal panel by panel adaptation in the anime but again, it doesn't always work like that. When reading panels a chapter structured like this one works perfectly fine when reading. Because you are reading text bubbles with images, sometimes entire one minute scenes in the anime come from one text bubble like with the book guy standing on his book as one example. During fight scenes in the manga single panel shots of punches being thrown have more impact, but when watching it in anime form (key word: animated) you have to constantly have things going on since it is a much more visual experience. Plus I think there's a reason Oda is often okay with the anime expanding on scenes such as the world of books because he admits he had to speed up the pacing during this arc in certain areas.
Don't get me wrong though. There are cases where the anime adds too many unnecessary scenes in that don't really need to be shown. One example of this I feel was the stuff in the Mirro-World but some people may disagree with me there too. It's just about perspective and none of us are wrong for feeling how we do, but at the same time you have to understand how different mediums work in the entertainment industry.