My bad about the pencil. This is the one that gives you that black color you were asking about. I don't differentiate between this one and my HBs since I carry all my softs together.
Actually since you mentioned it, I will have to disagree with you about Yoshitaka Amano. Yoshitaka Amano most definitely uses real models as well for his artwork. He often uses his own face to get the look he wants for the characters he draws. Here's a book you can read about it. He addresses this very clearly when asked about it by upcoming art students on page 25. Sorry, I don't have a color scanner but the cover is mainly black and white anyway. The resolution kind of sucks since the scanner is old. It never worked the way I wanted it to back in the day when I bought it to try and scan some of my work for a website. The guy who said he would build my site disappeared with the money I paid him for the job anyway so the machine just collects dust.
Anyway, enjoy the book!
Also, you are right about the difficulty of drawing realistic looking people out of your mind. That is what some of the other artists do who I have mentioned are way above me in experience. However, they continually check against the real thing for accuracy. This is why they show up every Tuesday at the local art studio to draw real models. I can draw certain positions very well without a model but others I do very poorly at in the absence of a model so I am continually trying to level my artistic playing field.
The two simple concepts of shading and flow are the two main things that have transformed my work from decent to better. There is some books that talk about how Michelangelo could make 5 different ascending or descending flawless shade changes in a single stroke with a pencil which is absolutely amazing considering that I average only about 3 and some of these artists who frequent the studio can do no more than 4. You ought to try to do this and check with a card to see what you can do. If you can do this well then there becomes less of a need to use so many different HB pencils since you can get multiple shades out of just one and you don't get that annoying line between shades that comes from switching pencils.