It's a fairly straightforward concept.
I coach cricket at a reasonable level. My batting is, and always has been, terrible. And yet I know exactly how to bat well. I know the stance you need, the technique, the temperament. I can tell somebody else how to do it, despite the fact I can't do it myself.
In an employment sense, I manage staff without ever having done their job. I know what they're supposed to be doing, however, and I know how best to do it. The idea that you must have experience of doing something to be able to understand the quality of someone else's performance is a fallacy.
But could you coach the England cricket team.
The Premiership is the highest level and I expect there is a lot involved in putting the team tactics together against other elite managers doing the same.