Il fratello di Shah, Omar Ali-Shah (1922-2005), è stato anch'egli uno scrittore e maestro Sufi; i fratelli hanno insegnato insieme per un periodo negli anni '60, ma nel 1977 "hanno concordato di essere in disaccordo" e ognuno ha seguito il proprio cammino. Dopo la morte di Idries Shah nel 1996, un numero considerevole di studenti si unì ai gruppi di Omar Ali-Shah.
Shah's father, the Sirdar , was expected by Graves to present the original manuscript to clear the matter up, but he died in a car accident in in November 1969. A year later, Graves asked Idries Shah to produce the manuscript, but Shah replied in a letter that doing so would prove nothing – the manuscript's authenticity could still be contested. It was time, Shah wrote, "that we realised that the hyenas who are making so much noise are intent only on opposition, destructiveness and carrying on a campaign when, let's face it, nobody is really listening." He added that his father had been so infuriated by those casting these aspersions that he refused to engage with them, and he felt his father's response had been correct. Graves, noting that he was now widely perceived as having fallen prey to the Shah brothers' gross deception, and that this affected income from sales of his other historical writings, insisted that producing the manuscript had become "a matter of family honour". He pressed Shah again, reminding him of previous promises to produce the manuscript if it were necessary.
Another hostile critic was , a Gurdjieffian who disagreed with Shah's assertion that 's teaching was essentially sufic in nature and took exception to the publication of a chronologically impossible, pseudonymous book on the matter ( by Rafael Lefort) that was linked to Shah. In a 1986 article in (now the ), Moore covered the Bennett and Graves controversies and noted that Shah was surrounded by a "nimbus of exorbitant adulation: an adulation he himself has fanned". He described Shah as supported by a "coterie of serviceable journalists, editors, critics, animators, broadcasters, and travel writers, which gamely choruses Shah's praise". Moore questioned Shah's purported Sufi heritage and upbringing and deplored the body of pseudonymous "Shah-school" writings from such authors as "Omar Michael Burke Ph. D." and "Hadrat B. M. Dervish", who from 1960 heaped intemperate praise – ostensibly from disinterested parties – on Shah, referring to him as the "Tariqa Grand Sheikh Idries Shah Saheb", "Prince Idries Shah", "King Enoch", "The Presence", "The Studious King", the "Incarnation of Ali", and even the or "Axis" – all in support of Shah's incipient efforts to market Sufism to a Western audience.