The Z-9WE is a militarized variant of the H425 civilian helicopter platform. The H425 was, in turn, developed as a civilian variant of the Z-9 military utility helicopter. The H425 is powered by a pair of Arriel-II turboshaft engines whereas the Z-9 is powered by domestic WZ8C engines.
The two Z-9 attack helicopters recently exported to Kenya are likely the new Z-9WE variant instead of the domestic Z-9WA. (here)
Military, civilian, what's the difference?