However, it appears to me that in most academic settings, one does not move up two or three tiers (assistant/associate professorships to chaired professorships, which are the new positions in this case) at once to a peer university at the top level, unless one makes an earth-shattering contribution, say an equivalent of the first successful self-driving car.
Apparently the Pearsons want four faculty members at the chaired professor level at this institute and two of the appointees to chaired professorships, though could be brilliant, do not yet have that level of name recognition in the field.
I believe the Pearsons argument is valid in this case unless the field’s criteria for promotion is very different from science, engineering, and computer science. What do you think?
If you're trying to build a vibrant research institution, one of the best thing you can do is to grab promising young faculty, rather than relying on senior faculty who are harder to recruit. Getting promising junior faculty, and using the institute's resources to position them for success - more hard money, better startup packages, support for staff and postdocs, etc. is absolutely a promising way to build what the Pearsons want.
And within the band of universities we're talking about, the variance between individuals is way bigger than the difference between those institutions based on rank - which is a problematic measure at the best of times.