Should cartoonist/animators make adjustments when modeling on model in Blender?

The crux of what I’m asking is this. I’ve heard of modeling ‘on model’, as in modeling based off of an illustration (in this instance, a person’s own illustrations.) However, I’m mainly talking about drawn objects, (such as guns, swords, tables, flamethrowers, or other polygonal objects). Should an artist model those objects based on their personal illustrations to a T, or should they adjust it to the grid system in blender (technically going off model slightly). I’m wondering how other modelers may have felt about this.