I noticed that in the Appendix chart Hinduism does not appear. Is this because Hinduism can be on any end of the spectrum because of its many beliefs?

You have expressed the exact reason that I don't write "Hinduism" anywhere on the chart. Madhva (under Dualism) is a Hindu author, and I have placed his position under dualism as a representative position in Hinduism. The range of authors in Hinduism, however, covers the full spectrum of positions on our chart.