Stephen Pressfield included a meeting with these displaced and cut off Israelites in his book, The Afghan Campaign. A novel of Alexanders campaign in Bactria on his way to India, from the viewpoint of a Macedonian hoplite.Along the wy they meet a tribe that they recognize as related to Israelites who practice the Passover sader in their own way.
I read a book by an English Officer, stationed in Western India, now Pakistan. He said some of the locals claimed to be descendants of Alexander's soldiers. He also said that the locality had a chain of hills, all with non-Indian, wild date palms growing on their tops. Local legend held that the date palms originally grew from seeds spit onto the ground by Alexander's troops, who were issued dried, compressed, dates carried from what is now Iraq.
The English Officer did not if that was true, but he said that if a General holding the territory to the West wanted to set out a line of pickets, to make sure no large army approached him unawares from the Indus valley, he would have chosen the hills topped with wild date palms.