Yeah going with the general main examples, Artoria, Mordred, Jeanne, and Nero all have very different styles of dress, and personalities plus general character tone. For example Artoria upon taking up the sword to become king became very stoic and emotionally suppressed, where as Mordred is very emotional and rebellious, so how they're drawn in terms of body language and general expression differs a lot. It's usually very easy to tell these characters apart once you're familiar with them in my experience.
Also yeah I still remember our old conversation where we agreed to disagree because you don't like most of the Fate anime, but Zero is generally different so you might like it. I have a friend that only likes Zero. Though maybe Fate just isn't your cup of tea and that's fine. I have a complicated relationship with the franchise, but also more than few people's worth of love for it as well haha