Two things.

One is size. An area this large emplaced as a single event means that there was a huge magma which supports the view that there should be elephant size deposits there and more then one (look at the extent and abundance of Chromite).

Two. A single magmatic event implies 'simpler' geology in the area. In the emplacement and cooling of a magma, heavy element/minerals drop to the bottom, light elements rise to the top of the magma chamber. On cooling you get distinct zones with distinct rock/mineralization. As a geologist hunting for mineralization you can extrapolate from where the Eagle Nest is to the chromite beds to look for nickle in relation to other chromite beds and so one.

In a multi-magmatic event magmas pass through previously emplaced magmas or host rock and create a much more complex geological puzzle. Understanding one particular area may not help you understand an area just a few hundred meters away.

In geology you hope for simple and usually get complex!

... Been There