If you are just rendering a still frame or an animation without changing lighting, it doesn’t really matter does it? You can just paint the highlights.
I assume you would paint it in in a texture painting software which lets you paint directly in the normal channel.
Even if you slightly tilt your head while looking at an object the highlights and shadows change according to your angle of vision.
I will have a camera moving around the scene, The lighting will not move but surely the highlights and shadows would need to adapt to the angle of the viewer.
Yeah, but if you want to paint texture maps, the way i understood it, i would assume you are making a stylized scene, so realism is secondary.
Regardless, if you really need normal maps, you need to either convert them from the albedo or paint them, ideally in substance painter or similar software. Otherwhise you may want lo look into krita which can apparently paint normal maps.
I believe you can paint multiple properties at the same time in painter, so a professional would build a material and just paint on the model with the albedo and normal at the same time.