LONDON (Reuters Breakingviews) - Credit Suisse has long tried to show that its “one bank” strategy added value to the Swiss lender. Now Greensill Capital has demonstrated how sharing clients between asset management, wealth and lending units can also increase risks. Though the financial hit from the supply-chain lender’s collapse looks manageable for Credit Suisse Chief Executive Thomas Gottstein, it exposes one downside of his strategy. The scandal affects almost every division of the Zurich-based bank. Credit Suisse Asset Management oversaw $10 billion of funds that invested in Greensill’s trade-finance assets. Founder Lex Greensill was a private bank client. Meanwhile Gottstein’s investment bankers advised the SoftBank Group-backed company on a planned capital raise, and the bank lent it $140 million. The relationship leaves Credit Suisse facing setbacks on several fronts. Start with the asset-management unit, which precipitated Greensill’s collapse when it froze its funds last week. Assets in three of the four funds are covered by credit insurance, leaving investors directly exposed to $1.8 billion. Strip out cash and loans to relatively safe borrowers, and there’s about $400 million of junk-rated exposure that could go bad. Though Credit Suisse is not liable for fund losses, Gottstein might have to cover them to avoid investor ire and lawsuits. Then there’s the loan to Greensill. Credit Suisse is confident of recovering the credit, which according to a person familiar with the matter is secured against cash and trade receivables on Greensill’s balance sheet. Conservatively assume the bank writes off half of it, or $70 million. Add that to the potential fund losses, and the total hit would be $470 million, equivalent to just 0.16 percentage points off the bank’s Common Equity Tier 1 capital ratio. Gottstein’s headache would get much worse, however, if Greensill’s credit insurance fails to pay out. Japan’s Tokio Marine, the main owner of the policies, on Wednesday told the Financial Times that it was studying whether they were valid. Whatever the financial outcome, the episode exposes deeper problems. Persuading the bank’s different business lines to work in tandem is laudable, but also makes it more sensitive to failures. Credit Suisse has been embroiled in a few of these recently, including German payments processor Wirecard and China’s collapsed Luckin Coffee, whose Chairman Charles Zhengyao Lu was a wealth-management client. Gottstein is doubling down on cross-business collaboration to hit his ambitious growth targets. Christian Meissner, a former Bank of America rainmaker, joined last year with a brief to help strengthen ties between the investment bank and wealth management. That’s long been the holy grail for Credit Suisse CEOs. Greensill shows it has a dark side.