These two solar systems were drawn for the same client, Nelson Canada, for two different grade levels. The top figure is for a grade nine text. The bottom figure is for a grade seven text. As you can see the amount of information and the complexity is increased greatly over two grade levels. In particular the grade 9 illustration shows the orbits of the bodies with far greater accuracy.
How to show the planet’s orbits when rendering the solar system is always a problem. If the entire disc of the solar system is shown in proportion (below right), then not only do all the bodies, including the sun, appear as tiny dots, the entire set of inner-planet orbits appears too small to show any detail. The diagram below on the left shows the inner-planet orbits in relation to that of Jupiter. Below and on the right, the orbits of all the planets are shown with the inner planet orbits tiny in proportion.
Therefore all solar system diagrams involve a compromise between accuracy and readability that can be determined by looking at the content the figure is intended to illustrate.