No one is going to have a full manufacturing facility if you are only going to pump out 3 trucks a day at most (given all the money wasted on the capital investment) on 3 separate "lines" (more like assembly stations).
I mean its operating income is about 2 million USD (I'm guessing its for only the vehicle assembly part because it doesnt make sense with everything else they do at their main website):
https://en.wikipedia.org/wiki/Bangladesh_Machine_Tools_Factory
It's just not the scale required for full manufacturing if those indeed are the numbers. So my guess is it imports the kits (either SKD or CKD) and assembles them. Thats the labour intensive process anyway, so it fits BD requirements well at current stage.
If you have any videos/proof on the capital machinery for any from scratch manufacturing, I'd of course love to be proven wrong. Same goes for the cars and such....is that done by another company? If so, which one?