I'd bet dollars to donuts that firms run by professional managers almost certainly have better security practices than family or founder run firms. I say this because research shows that professionally managed firms excel in virtually every other facet of operations and management[1].
Although I do not disagree with your comment, I would do a double take befpre accepting the source you cite because they are very much incentived to proclaim the result they proclaim.
[1] https://hbr.org/2011/03/family-firms-need-professional