Bond approaches Sanchez as a mercenary for hire of sorts, and Sanchez, the series' first villain of Hispanic heritage, like Scaramanga, brings him into his organization, in similar fashion to Scaramanga in the novel.
Sanchez has meetings with Asian businessmen/gangsters/investors over expanding his drugs empire; in the novel, Scaramanga and a group of hoods are looking to control the sugar empire (hey, they're both white powders!). It is also mentioned briefly that Scaramanga and his cronies are in the drugs and casino business.
Sanchez shows a certain "affection" or closeness to Bond, and though it doesn't quite have the homoerotic undertones of TMWTGG, it's definitely the chummiest Bond/villain relationship in the series. Sanchez is physically affectionate and touchy with Dario, though this can probably be interpreted as them just being "latino" - like Scaramanga! (Though has anyone wondered who exactly undressed Bond and put him in pajamas in Sanchez's home after he was rescued by Heller and his men? Did old Franz insist on doing that job himself?)
In TWMTGG, a KGB agent in Scaramanga's group identifies Bond. In LTK, an undercover Hong Kong narcotic officer in Sanchez's group identifies Bond.
Bond gets exposed as a traitor while on a tour of Sanchez's drug labs with the investors, and in TMWTGG he is unmasked while on a train with Scaramanga showing the gangsters around.
Finally, the names FRANZ SANCHEZ and FRANCISCO SCARAMANGA. Not a million miles apart?

So these are all some superficial observations, some or all can probably be shrugged off as coincidence, but do you think there's an idea or two here to suggest that Wilson or Maibaum flipped through the novel while penning LTK?