I also dont like how James Clavel handle the ending to one of his novel shogun, and the cliche affair between a more gentleman western man vs culturally abusive asian man, this kind of orientalist theme is nausetting for me.
I've read the novel and seen the 8-hour miniseries three times (twice in English and once in French). I'm not familiar enough with that period of history to know how much was based on fact and reasonably accurate and how much was just made up. But I did enjoy the miniseries (I enjoy anything with Richard Chamberlain, and any Sliders fans take note: John Rhys-Davies had a small(ish) role as a ship's captain).
Deciding how to end things can be a bit tricky for historical dramas. Real history is documented and shouldn't be messed with, so that's what annoyed me greatly about the European production about the Borgias (not the one I mentioned earlier). At the end of
Borgia, we see Cesare come ashore in the New World as a Conquistador, when in real history, he was killed in battle at Viana, Spain, and buried there. He never left Europe.
I guess the producers felt that ending the series with his death would have been too much of a downer, so they fudged it by saying, "Nope, history was totally wrong, it was just someone wearing his armor who was killed and everyone thought it was really Cesare Borgia who died..."

While emotionally satisfying for some of the audience, it was a cop-out for the rest of us. Sometimes a death scene is something to look forward to, if you know the actors, director, and writers are capable of doing it justice. Cesare's death scene in the American production would have been spectacularly poignant, given how good Francois Arnaud was in the part. But he never got the chance, since the series was cut short by a season.
Oh, well. What the producers don't deliver, fanfic writers will.