The SAs reflect the Services they feed.
Three different Services with a broad range range of missions, cultural differences, and warfare platforms/big gear/little gear. Of course they are looking for smart, healthy, fit, well-rounded candidates as a baseline. After that, it is art and science and long years of experience of choosing cadets and midshipmen, that goes into SA Admissions choices.
Navy missions focus on things on the sea, under the sea, over the sea, and from sea to land (Marine amphibious warfare). Army is land-centric. Navy might be arguably more STEM-leaning due to the big mechanical systems involved in fighting a warfare platform. Army might be more small-group leadership from the get-go.
There are many threads here on SAF that discuss differences. Depending on what context you are asking the question in, that can better direct the answers.
USMA and USNA are both experts in what they do. Much is similar, much is different. They are both giant leadership laboratories whose methods and goals align and diverge as their Services need them to.