Question about keywords

I'm planning a new blog and i thought i had a good niche, but now i have some doubt about the keyword results. Let me exlpain:
Let's say my niche is asian movie (it's not, just an example)

The keywords ->
asian movie = 400k searches, low competition
asian movie actors= 60k searches, high competition
asian movie awards= 50k searches, high competition
etc.

Now my question is: the "asian movie" keyword get's a lot of searches and there is low competition, however "asian movie actors" (and many other 3worded keywords)have high competition. Does this mean in reality that they also steal away rankings from"asian movie" or not? So if someone searches for "asian movie", will websites built around the keywords "asian movie actors" also steal away rankings from my website built around the keyword "asian movie"?

I hope this makes sense

They might do, they might not.

The only way to know is manually check, so who ranks for what.