I don't know any of those characters, except by fandom osmosis, but it sounds like ATLA has similarities with FMA - lots of 'magic' users, but also lots of normals who hold their own.


Yes and no, it depends very much on the area the main heroes are visiting at the moment. Katara is the only bender in her tribe, for example. And even if there are many benders around, the expectations of the people are very often that they can't do anything against the enemies, because they are too powerful. Or they think that it isn't their place, the Avatar has to do it. Sokka, Suki, Mai, Ty Lee - they really are pretty special. Not only in their non-bending abilities, but also in their agency.