That makes sense since, IIRC, the ADEN and DEFA share the same ammunition. *wicked chuckle* I can just imagine the French reaction to a Mirage IIIO with an Avon engine and ADEN cannons replacing the DEFA cannons.
Turning to my comment on the Macchi trainer thread, if most of the other Australian combat aircraft were using DEFA cannon, I could see the MB326KH also doing so; ontra-wise if most of the others were using ADEN cannon.