Harry won’t have any idea about money, that’s a given. TW had the idea to start up The Tig, so we know she has ideas and stickability, even if only small fry. However, earning money is only one aspect of wealth making.
I had a very successful Uncle who used to drum into me “It’s very easy to make money, but hell of a difficult to hang on to”. I suspect that the Dumbartons have no idea of asset building. Putting all their eggs in the McMansion at Montecito, taking on a massive mortgage, killing the golden goose KC3, doing said McMansion over in beige yawn-worthy Provençal wannabe hasn’t proven to be an Architectural Digest must see. Markle had never, on her own account, bought a house before her marriage to Harry. ( She rented in Toronto). So, I’m picking they don’t figure outgoings are as important as income. Fatal.