What this expression is conveying is not so much that this is the manner in which all risks are calculated (they are not) as much as that both of these elements must be present for there to be a real risk.
翻译：这句话想表达的是，这种方式并不是所有计算风险的方式，而是这两个要素必须具备才会有真正的风险。
修正：这句话所表达的是，与其说这是一种所有风险的方式，不如说只有具备的这两样要素才有真正的风险。
is not so much as+...+as.../is not so much that ... as much as that...
例句：Successful implementation of Channel Management is not so much as a question of supporting as many function as possible using software, as of indentifying the core areas and processes critical for bussiness in a particular industry, and concentrating efforts there.
成功的实施渠道管理与其说是运用一个软件支持更多的业务功能问题，不如说是发现一个发现某个特定行业核心业务范围和关键业务流程的问题。