What is the impact of culture clash in “One out of Many” and Death of the King’s Horseman?

Throughout much of the canon of postcolonial literature, the clash of cultures one character experiences leads to mental and/or physical trauma. Some examples are Okwonko in Chinua Achebe's Things Fall Apart, and Salim in V.S. Naipaul's A Bend in the River. Certainly, in Naipaul's "One out of Many" and in Wole Soyinka's Death and the King's Horseman, the clashing of cultures leads to trauma for characters and communities.
In Soyinka's play, the trauma the characters experience is set off by the bumbling interference of the colonial administrator Pilkings. The resultant suicides of Elesin and Olunde, like Okonkwo's suicide in Things Fall Apart, put an end to the community they were a part of. Now, the colonizers will tell their tale for them. Interestingly, a production note from Soyinka advises producers that Pilkings should never be portrayed as empathetic, sympathetic, or otherwise knowledgeable; he is in over his head and dealing with matters of which he has no understanding. The fact that it is a native of the tribe who tells Pilkings of Elesin's plans seems to suggest that the community was already crumbling from within.
In Naipaul's "One Out of Many," we see another kind of trauma affecting the protagonist, Santosh. As the title suggests, Santosh's desire to avoid living a life of anonymity in Bombay leads him to join his employer in the United States. Soon, Santosh realizes he is only one of many in the U.S. as well, in spite of his dreams of becoming a success. He is trapped between two cultures, sickened by himself and those who are kind to him, and must make the decision to return home and be perceived a failure, or live in a culture, and with a wife, foreign to him, but never found out. 
We might liken the personal experiences of colonization to PTSD in some ways. In his "Discourse on Colonialism," Aimé Césaire says, “A man screaming is not a dancing bear. Life is not a spectacle.” These tales show how the clashing of cultures, particularly under colonialism, have consequences; the persons suffering under the clash are not— and never were—artifacts.