These sort of decisions are made at a level where they want "support". A C(I|T)O wants someone that they feel that they can shout at if something goes wrong.

These sort of decisions are made at a level where they want "support". A C(I|T)O wants someone that they feel that they can shout at if something goes wrong. For you, with 20 nodes managed by yourself or a smaller team, CentOS / openSUSE / Debian / Fedora / Ubuntu all work. (They also work for much larger situations, but RedHat / SUSE will sell execs on "fleet management tools" and "integrated installers" "SSO" and access to the devs that wrote the software running on top, and extract a fee. Most companies would be better employing a few highly skilled people, but that comes out of a different budget)