This is an exercise that i want to see you doing! I would recommend making the matcap's identical between both. For this exercise, i want you to get out of the mind of 3d analysis, as in don't try to intepret and remember the 3d forms, and instead get into matching the shading exactly. Think like a painter, you are just…
Make the bevel at the width where it will be at least a pixel wide for most of the time it's being viewed. Or, two pixels wide if you think it's not too comically wide up close.
One pixel hard and soft brush. Three pixel hard and soft brush. Master the brush options(opacity,tipshape,texture and scattering). I need nothing else.
It's a simple logic . Normal map represents a pixel normal , a vector (direction) each pixel is facing in comparison to vertex normals (tangent one). So if you see it wrong there is only a few possibilities: a. the direction is wrongly recorded to the texture . Green inverted maybe or color representing standard is wrong…
Jocose: those squares in the rotor blades are 2x2 pixels, with a 1 pixel space in between. Hexagons aren't really possible due to technical limitations.