In some professions and fields and most academics I know believe academia is one…if the one managing researcher Profs has not himself done research at their level as a grad student or junior faculty at the very least, he doesn’t have the relevant experience to manage them…nor any business in doing so in the minds of most faculty I’ve known.
That’s not to discount his experience as a career military officer or his achieving the 3-star generalship.
However, that experience is so different from being a director of an academic research institute where one will be in charge of academic researchers with PhDs and decades of research/scholarship under their belts that much if it will unlikely to be applicable without some time experiencing the academic environment beyond that of an undergrad/MA level grad student.
Rarity of achieving a given position is irrelevant if the experience is so different as to be mostly/completely irrelevant to a new position.
For instance, being a Field medalist or a nobel prize winner is likely a far rarer feat than being a senior military officer/3 star general.
And yet, it would be absurd to use that as a basis to claim that automatically makes him/her qualified to be immediately hired straight out as the CEO/Senior exec of a fortune 500 company, field grade/senior professional military officer direct command of a military unit…especially at the regimental/brigade level or higher, etc without any other proof he/she has RELEVANT credentials/experiences expected in the hiring norms of each of those fields respectively.