I love toon shaders and I think it can help a lot of models based on 2D drawings look significantly better, but it needs some adjustments.
The models with toon shaders are too reflective.
Although I can see a tint of outlining edges (I think they are simply coloring inside the edges now), they are not well visible.
Here is a good example of a good toon shading:
I understand it may not look as well as that since Tower Unite isn’t built around toon shading, but I wanted to just illustrate it should look close to something like that.