From a few comments from RJ and Brandon, I get the feeling that there is something about the process that we don't know. I seem to remember a quote that the DO has orders of magnitude more trollocs than than the blight will allow.

First of all how many trollocs are there? A reasonable guess from the storyline is that there is around ten times more trollocs than light-side soldiers. That will put an upper-limit less than 100 million. Can the blight reasonably support that many trollocs (or 1/10th that amount if my statement above is correct)?

Well how does the food needed per trolloc compare to the food needed per human. At first glance it might seem quite large not necessarily so. A lot of it depends on the lifespan and support staff needed for Trollocs. Humans take a long time to mature and need significant amount of care to do so. At any given time only a small fraction can reasonably contribute to the fighting.

If a trolloc can grow up in half the time and then either put in stasis or immediately sent out to raid that makes a difference. If food can be kept for hundreds of years in stasis either through AoL tech or the DO that makes a difference as well. If they can only eat meat, that is a huge problem of course. But some fast growing blight creature might help with the aid of the DO. I would guess, though that the trollocs are given only enough meat to make them want a lot more. When they go on raids they only eat meat since it is readily available.

If we assume that a typical human can field 1/10 of its population as a viable army and a Trolloc army can field 1/2 of its population than a Trolloc army that eats five times as much would cost the same as a human army per army member. The trolloc army would also be easier to sustain assuming that they grow up quicker. Feeding 100 million off of the blight would be a stretch for 3rd age tech. I think it would be a walk in the park for AoL tech though. And who knows what the DO has up his sleeve. If we decrease the total sustainable number of Trollocs to 10 million, though, it sounds ballpark reasonable even without too much DO intervention.

This is probably over thought, though. RJ has been pretty good about a lot of details. I am not too sure about his understanding of population, though. I don't think there is a 'primitive' desert population that comes close to the population density of the Aiel for instance.