It always seemed to me that the use of the concept "mandala" in pre-colonial Southeast Asian history seemed to reduce the complexity of history, the interplay of strategic human agency and more fixed, long-term, deterministic structures, that one finds in well-written narrative histories, to a simple concept, a much too simple concept.
I've grown to appreciate the concept recently, and understand how some historians such as Sunait Chutintaranond, Thongchai Winichakul, and Martin Stuart-Fox have used the idea to pick apart received traditions about unified and centralized rule in their respective time periods and regions.
Sometimes the best way to gain an appreciation of an idea is to go through the laborious process of solving the problem that the idea was created as a solution to. After rereading Martin Stuart-Fox's history of Laos (see bibliography below) that uses the concept of Mandala extensively, I realized that the concept probably applies to nearby Mong Mao also. Furthermore, I read Chris Baker's paper that argues that the northern provinces of Ayutthaya were largely independent of the Ayutthayan center even into the period of Burmese invasions of the 16th century, but when I read Sunait Chutintaranond's paper, I realized that Sunait had already shown how "mandala" was the solution to this problem.
The world historian and historian of Burma Victor Lieberman's rejection of the term mandala in lieu of "solar polity" , "galactic polity" being yet another possible metaphor, is particularly instructive.
I still think that narrative history that closely follows primary sources is the best way to capture the interplay between strategic human action and long-term social and environmental factors in human and plan to follow this course in future research. General models that have been highlighted by Lieberman's Strange Parallels recently, including Gerschenkron's collective problems and advantages to backwardness, O'Connor's agricultural succession in Southeast Asia, and a general political anthropology approach, can clarify and highlight important themes in this narrative (without imputing abolute causal relations of different factors where multicausal factors is the norm).
Anyway, I've been slowly revising the Wikipedia page devoted to "Mandala (Southeast Asian history)". Here are my contributions to-date:
Mandala (Southeast Asian history)
Mandala means "circle of kings". The mandala is a model for describing the patterns of diffuse political power in early Southeast Asian history. The concept of a mandala counteracts our natural tendency to look for the unified political power of later history, the power of large kingdoms and nation states, in earlier history where local power is more important. In the words of O.W. Wolters who originated the idea in 1982:
"The map of earlier Southeast Asia which evolved from the prehistoric networks of small settlements and reveals itself in historical records was a patchwork of often overlapping mandalas"In some ways similar to the feudal system of Europe, states were linked in overlord-tributary relationships. Compared to feudalism however, the system gave greater independence to the subordinate states; it emphasised personal rather than official or territorial relationships; and it was often non-exclusive. Any particular area, therefore, could be subject to several powers or none.
Intersecting mandalas circa 1360: from north to south Lan Xang, Lanna, Sukhothai, Ayutthaya and Angkor.
TerminologyThe term draws a comparison with the mandala of the Hindu and Buddhist worldview; the comparison emphasises the radiation of power from each power centre, as well as the non-physical basis of the system.
Other metaphors such as Tambiah's original idea of a "galactic polity" , describe similar political patterns as the mandala. The metaphor of a "solar polity" is preferred by the historian of Southeast Asia Victor Lieberman because in the solar system there is one central body, the sun, and the components or planets of the solar system can be fully enumerated, unlike galaxies. 
History....The historian Stuart-Fox uses the term "mandala" extensively to describe the history of the Lao kingdom of Lan Xang as a structure of loosely held together "meuang" that disintegrated after Lan Xang's conquest by Siam starting in the 18th century 
The Thai historian Sunait Chutintaranond made an important contribution to study of the mandala in Southeast Asian history by demonstrating that "three assumptions responsible for the view that Ayudhya was a strong centralized state" did not hold and that "in Ayudhya the hegemony of provincial governors was never successfully eliminated" ....
ReferencesChutintaranond, Sunait, "Mandala, segmentary state, and Politics of Centralization in Medieval Ayudhya," Journal of the Siam Society 78, 1, 1990, p. 1.
Lieberman, Victor Strange Parallels: Southeast Asia in Global Context, c. 800-1830, Volume 1: Integration on the Mainland, Cambridge University Press, 2003.
Stuart-Fox, Martin, The Lao Kingdom of Lan Xang: Rise and Decline, White Lotus, 1998.
Tambiah, World Conqueror and World Renouncer, Cambridge, 1976.
Thongchai Winichakul. Siam Mapped. University of Hawaii Press, 1984. ISBN 0-8248-1974-8
Wolters, O.W. History, Culture and Region in Southeast Asian Perspectives. Institute of Southeast Asian Studies, 1982. ISBN 0-87727-725-7
Wolters, O.W. History, Culture and Region in Southeast Asian Perspectives. Institute of Southeast Asian Studies, Revised Edition, 1999.
1. O.W. Wolters, 1999, p. 27
2. Tambiah, 1976, ch. 7, cited in Lieberman, 2003, p. 33
3. Lieberman, 2003, p. 33
4. O.W. Wolters, 1999, pp. 27-40, 126-154
5. Martin-Fox, 1998, pp. 14-15
6. O.W. Wolters, pp. 142-143 citing Chutintaranond, 1990, pp. 97-98