Yes in hindsight it's clear they should have pushed the 3D a bit...

Yes in hindsight it's clear they should have pushed the 3D a bit further south to cover Dorado, but then you could make the argument that they could push a bit further in every other direction too. Eventually you have to make a call as 3D seismic is expensive.

I expect that with the Dorado result Santos will shoot 3D seismic over Dorado and probably a few other high grade prospects. As shown in that map you posted, the existing 2D grid is actually quite dense, though it could do with a few more lines over the Apus area.