Resource based conflict or ethnic cleansing?

I've just finished reading a great working paper, "Ethnic cleansing or resource struggle in Darfur? An empirical analysis", by Ola Olsson and Eyerusalem Siba, both of University of Gothenburg, analyzing the patters of attacks in 2003-04 in Western Darfur. They use a dataset of all villages and nomadic settlements in the region, and find that there were many villages side by side, where one was attacked and one was not. The difference? the resource based conflict suggests the one attacked would be closer to water, etc, the ethnic cleansing one would suggest it would be a Fur/Masalit/Zaghawa village. The analysis of 530 villages, of which 327 were destroyed or abandoned, finds overwhelming evidence that the ethnic composition of the village mattered. Basically only the Fur/Masalit/Zaghawa villages were attacked and destroyed. Wow- great work by Olsson and Siba.

I did send to them one suggestion for further work. While the distance to nearest wadi is a good proxy for village resources, there are four others that might be relevant, and indeed might even be measurable with careful analysis of Google maps:
1) gum arabic gardens
2) tebeldi trees (baobab trees) - before boreholes these were important source of water, and many settlements sprang up and tended baobab for water storage; alternatively boreholes should be mappable, no?
3) wadi gardens with 10km of village (many anecdotes suggest that capturing villages where these fruit and vegetable gardens existed was a factor in pattern of assaults)
4) pasture - I wondered if merging the data with recent two decades of NDVI indicators might also prove fruitful in giving more nuance to patterns of attacks?