i'm not sure about the footwall terminology, this is an old mining term usually reserved for shear and vein hosted mineralisation.
in the description and the cross-section they refer to a dome, so to me porphyry style fluid accumulation is more appropriate - or given that they are sedimentary rock hosts then a fluid trap on top of a dome. domes are excellent fluid focusing structures, so i'd be focusing on that aspect as it is easier to explain, simpler to target, and the target/prize is bigger - in my experience anyway.
how big can the prize be? the golden mile in kalgoorlie sits on top of a dome, need i say more.....