Yeah, that would work, but the issue is that if you want to support "every" SaaS company, you need to solve the problem of integrating an SaaS product that does not offer granular permissions. e.g. An "admin" account that could grant/revoke access to users might necessarily also have access to sensitive company data.
In fact, it's the sensitive data that is the issue that will generate the most resistance from potential customers. Companies probably care way less about trusting you with their credit cards than they do with trusting you with sensitive vertical-specific data. THEN AGAIN, people are putting their entire company communication into Slack so who really knows...
