A leader doesn't have to be an elected or appointed official that is in charge of a country. Anyone who garners influence and gains a following can be considered a leader. Gandhi works.
Gandhi was certainly an important leader within his country and an important figure in world history, but I think the term world leader usually implies the head of state or head of government of a major power, which he never was.
Because the H doesn't serve any phonetic purpose (at least with how it's pronounced in English) but people know it has an H, so they associate it with words like "ghost" and put the H after the G. There are no words (that I can think of) with the H after a D, except for Indian words like "dhoti" which are not that well known.
I'm not Indian but I believe speakers of Indian English would make a phonetic distinction between 'Gandhi' and 'Ghandi'. The H indicates aspiration of the preceding consonant, an audible puff of air on release. I agree with your explanation otherwise and would be tempted to misspell it myself for the reason you gave.
Is it accurate to call Gandhi a "future" world leader? The peak of his influence chronologically coincides with much of Mussolini's regime... and he only survived a few years longer than Mussolini. Wouldn't "contemporary" be more accurate?
My father collected autographs in the 1920s, when all you needed to do was write famous people to ask for one, enclosing a SASE. He got Mussolini's, Edison's, Toscanini's and others' that way.
Mussolini's signature was a series of violent vertical strokes. I'll give you one guess which current political figure's signature resembles Mussolini's.
As an aside, the trains did not run on time any more often under Mussolini.
Answering to the popular cliché: "Say what you like about Mussolini, he made the trains run on time" Massimo Troisi, a late Italian actor, said: "Wasn't it enough to make him a stationmaster?"
good quiz, btw!
https://www.jetpunk.com/user-quizzes/1277141/the-dictator-files-vladimir-lenin
Mussolini's signature was a series of violent vertical strokes. I'll give you one guess which current political figure's signature resembles Mussolini's.
As an aside, the trains did not run on time any more often under Mussolini.