I took the cue of what I personally like in the simplicity and symmetry of the "List of 16", and try to construct something "simpler," based on the still somewhat complex distribution scheme - 9 texts for Western, 6 texts for East Asian, 6 texts for South Asian, and 4 texts for CWANA - this preserve the ratio envisioned in the List of 150.
CWANA is already existing (based on List of 16): Quran, al-Tabari, Ibn Sina, Rumi. One for each genre, 1 Persian language work that also covers Sufism.
East Asian: I figure that my issue is that I am too "ingrained" in the Buddhist tradition, and thus made some text selection based more on personal preference than actual influence. The 6 texts I am thinking now are: Wang Bi, Sima Qian, Zhuxi, 300 Tang Poems, Jingde Chuandeng Lu, and Tale of Genji.
South Asian: this is tougher, again as there is too much to include - besides the Sanksrit mainstream, has to include something on Buddhism, Bhakti and Islam right? 5 of them is clear: Rg Veda, Samyutta Nikaya, Samkara's Brahmasutrabhasya, Mahabharata, Kalidasa. I am ok to not include Nagarjuna (but then the question is, is this "giving up" an objectively defensible choice based on influenc?); but couldn't decide among Adi Granth (Sikh scripture, but composed mostly of devotional hymn that is somewhat of a confluence of bhakti and Islamic piety, in general characteristics similar to Rg Veda though), or Akbarnama (history work, in Persian; this will give up bhakti, and as a work it is more exemplary, maybe representative of the historical tradition by Muslims in Persian, but clearly not as influential as Nagarjuna), or Amir Khusrau (emblematic of the beginning of a native South Asian Islamic tradition), or Gita Govinda (Vishnaivite bhakti poetry).
Western: with 9 works, the simple rule is to spread out 3-3-3 for Greco-Roman, Christian and modern European. (This is the key to break-out the 2-2-5 allocation in the original List of 25)
Greco-Roman: same as those selected in the List of 16: Herodotus, Plato, Virgil.
Christian: Bible, Augustine, Eusebius (the last represents history, probably less "in vogue" than Dante, but represents the Greek-side of early Christianity - the history is also foundational for western medieval historiography).
Modern European: Kant and Shakespeare are clear. The last one is harder to decide - I am thinking either Tolstoy or Dostoevsky (gives good balance, English, German, Russian all represented; also covered 17th, 18th and 19th century; plus it includes a novelist which is the most dominant literary form since the 19th century, and hailed from different strands of Christianity); or Victor Hugo (to represent French, but how about Voltaire?); but influence-wise can a Tolstoy or Dostoevsky or Hugo compares wtih Marx?