I'm fascinated by your point on Myanmar/Burma since I'm quite sure you used that point since it's common knowledge that is the most commonly cited example of the use of in situ firearms by militia. Maybe you're inviting a debate on why you think the reports on in situ firearms reported there are false, or maybe you just randomly came upon that, but it doesn't seem a coincedence.
Myanmar/Burma the strategy was build-to-capture: make improvised, unreliable firearms that could be used to ambush security forces and take their firearms.
Evidence against the point above that it's trivial to replace professionally manufactured small arms.