In contrast, my mental model is that it is only worth knowing a little or a lot. The middle ground is only useful when you are filling a gap.
* If you know a little, you know enough to reason about the topic and identify how you can outsource your needs. eg, you know enough about accounting to pick and manage an accountant. * If you know a lot, that's your value add and you can provide that service.
Where if if you know a "medium amount"... * you still need to outsource to an expert most of the time * or you can't find the right set of expertise to outsource to and you must fill the gap yourself.