Apologies, I wasn't very clear about the hair. When you change shade, it's a chance to reinforce the texture you're trying to convey. So the combination of tufty and smooth transitions are a bit confusing on the same object.
So keep your transitions tufty, but the tufts don't need to extend so far down the head as they did in the original. In fact, the brightest hair colour in the original was doing a great job and didn't extend very far at all.
And it can look better when the transitions are a bit more bunched up at the extremes of the gradient. This means a large area of hair will be represented by one colour and no texture, but you don't need to be afraid of that.
Texture can be conveyed with a small amount of detail in a sea of a single colour. With limited colours, this can look a lot better than trying to spread 4-5 colours evenly across a grad. If you're working in high res, the opposite may be true depending on the style. A grad can look good because you have millions of colours at your disposal. I suspect that in most cases you'll still concentrate areas of light and dark though.
A way to think about hair might be to imagine it as a solid lump of shiny, smooth material. Shade appropriately, and add a line of glint/highlight. Maybe another larger area of lesser highlight around it. And when I say 'shade appropriately' I mean finding a line to draw your shadow, effectively using two shades for 'lit' and 'shadow'.
Now you can rough up your highlights in the direction of the strands of hair. Like I say, your original highlight does this well. Do the same to the transition to shadow.
At this point you may want to think about the texture of the hair you want to convey. If it's dreads or a spikey Manga style you'll want to add shadows and/or lesser highlights to identify individual tufts. If it's curls you might want to pick out individual curls around your transitions and add highlights and shadows. If it's straight you may want to add shadows around the tips where the smooth hair breaks up into tufts. Unless it's recently cut and heavily styled hair, where you can get away with straight lines and minimal texture.
Here's something I found randomly that shows a few hair types.
https://www.hiclipart.com/free-transparent-background-png-clipart-tsshrFor the characters with long hair, there are few colours, and the highlights and shadows are kept relatively close to the tops and tips respectively. In most cases there are long areas with no texture or shading, and that's OK because the shading at the transitions carries it. The different transitions don't often come near to overlapping.
This is a good example because it also shows a character with hair that requires tuft-by-tuft shading as well. It looks like a similar way you might shade a palm tree or a pineapple for example. Looking at your character you may want to do that around the tuft at the right-hand side.
Looking at the above example, one thing I notice for long hair is that hair on the top of the head is lit, while on the side it's in shade. This feels natural if the light source is coming from above. In your case, the light hair carries on half way down the side of the head, and I'm struggling to think of a light source that would do that.
This is a lot of words. If I get a moment today I'll try an edit.