Schmedlap,

I read the paper a couple months ago and, like you, found it compelling. I haven't seen any critiques either.

There was a discussion over at Col. Pat Lang's blog on this topic and he's advocated an approach similar to what's proscribed by Maj. Gant. Col. Lang was also an adviser to the HTT program. I asked him his opinion on the apparent discrepancy between between the two papers regarding tribes. His reply (in the comments to that post linked above):

Some of the HTS crowd are perforce deeply committed to the social science method of looking at just about everything. That means, in this case, that one studies some phenomeneon at the smallest scale possible, with the greatest rigor, and little tolerance for intuition.

UW methods like those promoted by Major Gant work with any set of groups that have self identity in numbers small enough to be affected by you. Villagers, tribesmen, people working on collective farms, moshavniks. You can name any number of categories.

They have to have some leadership. If not then you can provide it yourself. They should have a perceived grievance. Movies are fun. I remember the Nuristani/Kaffiristani villagers in "The Man Who would be King." Their grievance was that the villagers up-stream were "pissing in the river."
That's about all I've seen besides the Ghost's of Alexander posts you linked to above.