I don't think "getting it right" is a good way of phrasing it. The aspects of Eastern philosophy you mention seem more relevant to Western ideas like phenomeno

I don't think "getting it right" is a good way of phrasing it. The aspects of Eastern philosophy you mention seem more relevant to Western ideas like phenomenology, monism or pantheism. The identifying feature of existentialism, as distinct from phenomenology, is the focus on the inescapable responsibility that our individual freedom places on us to create our own meaning in life and accept our own ethical behaviour and value system. It is an individualistic and atheistic perspective. The phenomenological aspects are more psychological than the Eastern works you mention, which are more metaphysical. You say "I am not sure that classification of philosophies and philosophers is of any use", but you raised the issue of the classification and its origin.