Looks like the brother just does the merges? (which are mostly automatic) so IMO best it matters because it's still mostly a one man, or at least a one family operation - i.e not very resilient to random acts of nature (which backups are supposed to protect from)
Having them be two brothers makes for a lower business continuity risk than having it be a business owner + 1 random employee.
Yes. Having family help out on a 1-man show is an entirely different beast than hiring a full-time employee with wages, taxes, and healthcare. One of these two is a life-long trusted human that you've shared numerous life experiences with, the other is not.