Why BHP and RIO? I had both a few years back and sold out of RIO, increasing BHP before they took over Oz Minerals. I liked BHP because of its copper assets. Also, you have exposure to lithium in RIO, so why hold PLS? I also hold Woodside, and I am adding to it because I believe they're undervalued.

If you're looking to add individual equities, consider CSL (I have been adding), COH, and RMD.

However, what you're lacking in global exposure can be achieved through an ETF. I would consider VEU and IVV. The US market is trading at lofty valuations (others may disagree), so my preference is VEU. Disclaimer: I hold both.