A versão do O Sinal dos Quatro que está no site do Project Gutenberg diz:
Two Sikh troopers were placed under my command, and I was instructed if anything went wrong to fire my musket, when I might rely upon help coming at once from the central guard. As the guard was a good two hundred paces away, however, and as the space between was cut up into a labyrinth of passages and corridors, I had great doubts as to whether they could arrive in time to be of any use in case of an actual attack.
"Well, I was pretty proud at having this small command given me, since I was a raw recruit, and a game-legged one at that. For two nights I kept the watch with my Punjaubees. They were tall, fierce-looking chaps, Mahomet Singh and Abdullah Khan by name, both old fighting-men who had borne arms against us at Chilian-wallah. They could talk English pretty well, but I could get little out of them. They preferred to stand together and jabber all night in their queer Sikh lingo.
E:
"'Then my comrade and I will swear that you shall have a quarter of the treasure which shall be equally divided among the four of us.'
"'There are but three,' said I.
"'No; Dost Akbar must have his share.
E, tanto quanto me lembro, esses eram os nomes que eu li em O Sinal dos Quatro .
E, como eu me lembro, os críticos comentaram que Conan Doyle deu seus nomes muçulmanos Sikhs por engano.
Aqui, por exemplo:
4) the 3 Sikh men are Mahomet Singh, Abdullah Khan and Dost Akbar. but all Sikh people have Singh as their last name. besides, Khan and Akbar are Muslim names, not Sikh names.
e aqui:
And sure enough, the Indian names in The Sign of the Four are likewise improbable in the highest degree. Scholarly attention has concentrated on the names of the Four themselves: Mahomet Singh, Abdullah Khan and Dost Akbar, all of whom are definitely presented as Sikhs (“Punjaubees”, natives of the chiefly Sikh province of the Punjab). Says Blakeney: “These three Sikhs have names that Sikhs would not own.” T. F. Foss, writing in 1968 without reference to 1 ‘Thoughts on The Sign of Four’, SHJ 3 no. 4, summer 1958, pp. 6-8. 10 The LOG Blakeney, makes the same observation,2 and is particularly hard on “Mahomet Singh”, though he manages to misspell it: “‘Mohamet’ is the name of a Mussulman, while ‘Singh’ is a Sikh one, and to a lesser degree, also a Hindu one.” By “Mussulman” Foss, who is affecting Victorian chauvinism, means Muslim. “Mahomet” is the old-time spelling of the name of the Prophet, more commonly “Mohammed” and more recently “Muhammad”. And “Singh”, or “lion”, is the universal adopted name of Sikh males, though it is also used by some Hindus. Dost Akbar and Abdullah Khan, Foss plausibly says, are “Mussulman, and no nonsense about it”.
John Linsenmeyer in 1975 similarly declares that no Sikh would be named “Mahomet” or “Abdulla” or “Khan” or “Akbar”, these all being Muslim words or names.3 Exaggerating a little, he compares the three Sikhs with their improbable names to “three Jewish convicts named Gamel Abdul Nasser, Francis Xavier O’Herlihy and Baron Frits van Poot”. In the same vein, Andrew Boyd in 1961 had suggested that “Watson might as well have claimed a knowledge of Scotland and then set down a tale about three simple Highland soldiers named Venizelos, Vasco de Gama, and Voroshilov.”4
Otis Hearn in 1972 suggests that Watson unconsciously replaced authentic Indian names with the sort of name he would have heard during his own experiences in Afghanistan, where there are indeed Muslims rather than Hindus or many Sikhs.5 An editor’s footnote to his article refers to a real-life malefactor who went by the name of Mahomed Singh Azad, but it seems to have been a pseudonym, and not a particularly convincing one.
Essas citações devem ser suficientes para convencer até mesmo pessoas que ainda não conheciam as diferenças entre nomes muçulmanos e nomes siques que Conan Doyle selecionou nomes muito improváveis para seus personagens sikhs em
Quando Conan Doyle escreveu, os imigrantes muçulmanos e siques para a Inglaterra eram poucos e politicamente insignificantes. Mas, na época das adaptações de Granada, as comunidades sikhs e muçulmanas no Reino Unido eram numerosas e politicamente mais ativas, e os cineastas talvez quisessem evitar ofender as duas comunidades ao parecer confundi-las. Eles fizeram muitas outras mudanças nas histórias originais para encaixá-las nos horários ou por várias razões aparentemente inexplicáveis, então fazer uma mudança para evitar controvérsias parece ser uma razão muito plausível.
Esse é o meu palpite.
E obrigado por fazer a pergunta, levando a uma pesquisa agradável.