This, too, is a rather tough-to-judge match for me.
The monochromatic palette in Nord's entry is very effective, a very fine tightrope act in colour use. Great metallics, too.
Benbow's entry is more lively, but still very well-consolidated, and the attention to detail in the staging of the photo is a delight.
Both entries immerse me in their respective atmospheres. On that count, I'm more fond of the "African adventures" atmosphere than the "Newhammer 40K" one, and I might just have to let that be the tie-breaker for me, subjectively.