the diesel fuel in Pakistan is ULSD.
The reason the 1KD injectors croaked and died were because of the bad design and control system of them. Toyota updated the parts 2 more times to correct this issue and had to give free parts to thousands of customers.
if you look around you will find a lot of mercedes CDI engines running with no problems on the same fuel. Their smoking is due to mechanics not following correct procedure.
The reason for this engine swap must be due to cost - the cost for 4 injectors, the high pressure fuel pump, the pressure valve and sensor along with installation and calibration is almost three times the cost of a toyota 1KZ from scrap.