At the risk of frying Turk1964's brain (and I suspect it wouldn't take much), I shall continue with the thread.
I have included four maps to facilitate matters (and hopefully perhaps spur some interest and constructive discussion). There's one satellite map, two Köppen climate classification maps and one soil moisture map. The satellite map is probably the most helpful as it most directly informs about terrain colour, but all the maps have their usefulness. I have cropped and resized the relevant maps - links to the original sources can be found at the end of this post.
Fig. 1: Satellite map
One should hopefully be able to see that the colour of the land mass can vary quite considerably, with Europe a green colour and North Africa, the Middle East and Central Asia largely a more sandy "arid" colour.
One may also be able to spot that some areas, such as the Iberian Peninsula or Asia Minor show a mixture of green and arid terrain.
Fig. 2: Köppen climate classification map A
This is is the first of two Köppen climate classification maps. The Köppen climate classification is one of the most widely used climate classification systems.
- The red and pink areas represent desert (arid) terrain.
- The green and blue represent green areas (Maritime Temperate climates or Oceanic climates and Continental climates respectively).
- The beige areas, for example in the Iberian Peninsula, Asia Minor and central Asia, represent cold semi-arid areas.
- The yellow and khaki (e.g. in Portugal) represent Dry-summer subtropical or Mediterranean climates.
Fig. 3: Köppen climate classification map B
Another Köppen climate classification map. The yellow and beige areas are arid, the dark green and purple areas represent green climate and the light green represent warm temperate hot/dry summer areas.
Fig. 4: Soil moisture map
This map shows soil moisture and echoes the other maps. The keen of eye will notice, however, that the drier areas of central Asia expand further North than the climate maps would suggest. Wikipedia explains this thus: "much of central Asia, northwestern China, and southern Mongolia have a thermal regime similar to that of the Dfa climate type, but these regions receive so little precipitation that they are more often classified as steppes (BSk) or deserts (BWk)."
Map links:
http://en.wikipedia.org/wiki/K%C3%B6ppe ... sification
http://koeppen-geiger.vu-wien.ac.at/present.htm
http://www.nrcs.usda.gov/wps/portal/nrc ... 2p2_054017
I am happy to review and redesignate the armies with the additional information - for example, ancient Judaea could perhaps be green or arid rather than arid.
If anyone wishes to offer constructive discussion then they are welcome to do so.