Might want to update your table a bit:
In general, "expertise" for a given distro depends heavily on what you're trying to use the OS for. If you're supporting an Enterprise application or a workload that isn't well-aligned to a given distro's design-philosophy, the expertise-required goes way up (e.g., if you're trying to maintain a bleeding-edge development environment, RHEL/CentOS can be paaaaaaainful when trying to to keep your language packages — and the like — something resembling "current"). If you're just using a given distro as a casual-use system, the expertise required generally trends markedly downward.
Another thing that ought to be a point of consideration for a distro-choice is, "how much of what I learn about this distro can improve my employment options and potential salary". =)
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.