2 types of needs for light. SEEING and BEING SEEN. To be seen is easier because you can use cheap options mounted randomly and it all helps. To SEE you need strong lights to reach as far as possible. That strong light needs to be focused to help it reach farther down the road. The farther you can see, the longer you have to react to what you see. Low-mounts lose most available light into the road surface sooner than high mounted lights do. Lastly, we have binocular vision to triangulate objects as we approach them. High-and-wide mounts aid that binocular triangulation as far as possible.
If you want filler to see the edges of the road in areas where the brush encroaches on the road and the distances are shorter, you can address that, again with strong pencil beams and cross-aim them so the left beam points to the shoulder and the right beam (US right-sided-driving) is aimed down the road. It makes the pencil beam more adaptable than wide-beamed close-work choices.
So strong pencil beams, mounted as high and as wide as possible if you're wanting to SEE.