If you take long-term deterministic structure, environmental or social structure, versus chance-contingency determined good-ole strategic human agency, which one do scholars tend to focus on and theorize about, the deterministic, of course.
That's why Niall Ferguson's finding that the counterfactuals that human actors proposed before the actual events happened is such a wonderful entry into neglected human agency:
“…historical accidents are products of collisions between chains of deterministic causation” (Niall Ferguson, Introduction to Virtual History, p. 40). What about:
1. deterministic causation works at the level of the localities or regions
2. the collisions are strategic military alliances between elites
3. elite circulation, travels or communications, were the basis of these alliances
4. the accidents were the changes from the deterministic trajectories that this human agency brought about
There were some very loose alliances in early modern Southeast Asian history, for example the Shan confederation that ruled over Upper Burma (c. 1527-1555). During this period there was no real centralization, consolidation around the Avan center.
References to relations between regions such as Chiang Mai and Mottama (From Binnya U 1364 to Dhammazedi c. 1458-1492) both military and religious occurred at intervals during the 14th-15th centuries, they all but cease during the massive centralizations of the 16th century.
Expanded pool of examples:
1. Si Lun-fa’s confrontation with his Ming conquerors (1382-1398)
2. the frequently changing loyalties of the Mon-Ava Wars (1385-1425)
3. Prome’s cooperation with Si Lun (use Tai name) of Mong Yang (1527)
alliance prior to founding of Ava
5. Phitsanulok Thammaracha’s alliance with Pegu against Ayutthaya (Chris Baker)
4. Tabinshweihti’s assassination and a Mon restoration for two years (Pinto)
6. Rebellion, Bayinnaung campaigning in Chiangmai (Than Tun) (c., 1557)
7. Christian Daniel’s paper on Chinese usurpation in (c. 1580)
8. Alliance of Nan with Lan Chang against Chiangmai in my first paper (1590’s).
list of strategic military alliances:
9. Minhkaung requesting help of Chiang Mai when he marches against Pegu (c. 1403)
10. Razadarit requesting help from Hsenwi (c. 1415)