@Jaycen Hi Jaycen!
Okay so there are three things to know about this.
First, your examples are very stylized characters. The more cartoony, the more extreme the expressions will be. Subtler expression will work better on more realistic characters. On very stylized characters, it'll mostly just look blank or unexpressive.
The second thing is more complex. We humans can detect a large range of emotions in real life, but in a drawing that scope is always diminished. A lot of the cues we distinguish in real life are so subtle that it only works o n a real living person. Sometimes it's so small that we need to be able to see the before and after (in real life or video) to even notice the shift. That cannot be captured in a photo and even less a drawing. Moreover so many of these signs are completely subconscious that duplicating them consciously is very difficult if not impossible. I became more aware of this when I studied film animation. So much of what I took for granted are difficult to express and you have to study people almost obsessively to reproduce it. I once attended a 2 hour conference that taught how and when humans blink. This is a great example of something that a drawing cannot capture: our blinking communicates a lot of subtle emotional cues.
Third and last thing goes back to the style. The more stylized, the more you lose information and to compensate you have to make the character more expressive to communicate the same emotions. Have you ever hear of rotoscoping? A few decades ago someone had the idea of filming people, then printing out the video frame by frame and tracing it by hand. In theory, a fool proof animation technique that would make incredibly realistic animation! In practice... a horrible flop that looked terribly wrong. For a long time people couldn't figure out why it worked in film but not animated. It's the same movement right? But it looked bad, inexpressive, weightless. Because of the information that is lost in the animation process, the movement has to be exaggerated just so it looks natural and normal. The same principle applies to drawing, if you try to go real subtle like a real life expression, chances are it'll just be kind of neutral and people might not be able to tell what emotion is. In a comic or any story it's so important that people know how the characters feel. Having everyone look blank is a recipe for ruining it entirely, to be frank.
TLDR; you can go more subtle if your characters are very realistic, but you'll still have to play it up a bit just so people understand what emotion you're going for.
