Anything can be looked as a slippery slope, to any direction. "Too little of this can lead to X. Too much of it can lead to Y." This kind of thinking only lays out general possibilities, and doesn't really tell which one is more or less probable, nor helps to describe what actually happens. Of course that a minimum level of internal coherence must exist in a work of fiction, otherwise the suspension of disbelief would be broken, or might not even come to be formed, but you can have many different degrees of detailed, explicit layout of such fictional setting rules. You can have from just a simple short story without any form of worldbuilding, as Poe's works, to Tolkien like fantasy or Star Trek science fiction level of deep exploring of internal structure. One is not better than the other inherently, it depends on what is the purpose of the work. If the author is writing a novel that happens on the real world, he only needs to explain what is directly related to the plot, the characters, or the general message his work is trying to say. Fantasy and science fiction need more explicit setting of internal rules just for the general context and background alone, yes, but there's always a point where the explation is unnecessary, for any type of work. No one needs to know exactly how Superman's cells turn solar energy into heat vision, or how Achilles was invulnerable, to accept and apreciate their stories. When said detail or inconsistency is not important enough to risk the coherence of the work, it may be cool to adress it and give it a reason, and it might also just draw the attention of the public to something problematic that was ignored until the moment, crippling the work instead of solving the problem. Explaining is not always the better thing to do. Sometimes, it is done just for fun, just because it is cool to know how a lightsaber works, which always is a luxury, so to speak. Too much of it can become a huge distraction from the center of the experience, be it the plot of a narrative or the gameplay of a videogame. In Samus' case, her armor looks disproportionate because it is aesthetically better for its purpose: to look cool, intimidating, and alien. And gender ambiguous for the most part. If it does that in the end, it's what matters the most, and it comes down more to personal preference wether or not it badly needs a stated, in universe, reason. Many visual media characters have odd proportions just because of the aesthetics, and aesthetics are not trivial. They are also a narrative tool. The Joker's face is the way it is to tell something about his character just by looking at him. In some continuities he is not even stated to be disfigured. The Penguin also is not always stated to be born deformed, just a chubby guy with a pointy nose in a smoking suit. Their looks themselves are more important than the fictional reason behind them.



This leads to the next point, of wether Samus' Chozo DNA backs up the frail, too ordinary looking physique of hers. The point is her physique tells something about her character. If she is said to be one of, if not the fiercest bounty hunter in the galaxy, capable of wiping out entire planets alone, defeat monster after monster of the likes of Mother Brain and Ridley, and being genetically modified on top of it all, but doesn't look very much like it, it weakens these traits of the character. It seems forced, like we are told to believe that despite of what we actually see. Oh right, some characters pull this trope, of the unassuming powerhouse, but it is not the case here. Samus is not some Omega level mutant with mental or energy based powers unrelated to physical condition. Colossus is super strong, as the Hulk, and they show it even if their strength is not a normal effect of muscle size. They show it because it would not be very harmonical to portray them without a muscled physique, making their superpowers less believable. The Flash is super fast for entire fictional reasons, and still he is not buff or fat, but lean. It's the same thing with Samus. If she does what she does, even with powers, her lifestyle would demand a lot of her body nonetheless. And it is not only about how to harmonically portray a character's powers, but his or her personality as well. If she looks like a model, it tells, even if only implicitly, that she is more like a vain girl than like a warrior, and so it gives conflicting signals about her in the end. What should we believe in, the textbook backstory, in how she acts as we play as her inside the suit, or in how she looks outside of it? You are right, generic sexy fighter is not what her character is about, and vain girl who kicks ass also is not. I just don't think her alien genes shrug off that easily this kind of visual contradiction.



As to the Wonder Woman vs Swuimsuit Model figure, I didn't mean to say that Wonder Woman's shoulders were that wide, but they are generaly a bit wider than those of any normal woman, without looking un-feminine, and that kind of artistic proportion might seem less contrasting to the armor. We don't disagree much on how she should look. I would leave the armor as it is, and only narrow the contrast with a more amazonian/Super Metroid figured Samus. At least her height should be roughly the same as the armor's, unlike in Other M, where she gains an entire head inside the suit, like those size changing transformers.