What would benefit Western plains is a complete rebuild of there elephant area. This idea that the herd needs an indoor barn for them all to fit in is absolute rubbish. Both Werribee and Monarto have harsher winters, I will die on this hill. It's nothing more than a waste of money for either an extra cafe or elephant experience. It does not benefit the elephants and wastes space.
What would be better is to build two new modern barns for night accomodation. With two paddocks for bulls with a couple of smaller musth paddocks attached. Then building two larger paddocks for the matriarchal herd. They would be Able to build larger paddocks, create a more fission and fussion holding style for the elephants. While being able to seperate bulls of when needed but having two large paddocks to have them in during the day allowing multiple bulls to be held together. Bulls are not solitary, the overwhelming majority of the live and semi cohesive groups of bulls. Which is usually headed up by a large mature bull. They then seperate out when musth hits. Western plains if it had larger bull habitats, that were actual elephant habits (I've seen cattle paddocks have more depth to them and look and function better). They would be able to house the bulls together easier.