As an analogy, a MacBook is a type of laptop, and laptops, desktops and tablets are all IT devices (for lack of a better word). Apple might have you believe that a MacBook is very different from a laptop and belongs in its own category, but to me I would still lump it under laptops. If I was presented with a MacBook, a desktop and a tablet and was asked to pick out the laptop, then it would be clear to me that the MacBook is the correct choice.
Now, midori (green) is a type of ao ("grue"), and ao, kiiro (yellow) and aka (red) are all colours. English speakers argue that green is very different from blue and that they're different colours, but to Japanese speakers ao encompasses midori. If a Japanese speaker was presented with the colours green, yellow and red and was asked to pick out ao (in the context of traffic lights), then it would be clear that green is the correct choice.
There are loads of situations where words in two languages seem to directly correspond to each other, but still they are subtly different especially when the nuances of the words are considered.