I'd have to suggest that the 'default' list (eg this one) should be the most general and beginner oriented, and any new additional lists should be the ones with the narrower focus (centos-tech, for instance, or centos-sysadmin). in my experience with running multiple lists, unless there's a near-nazi level of 'DO NOT CROSSPOST' enforcement, half the traffic will get crossposted all over the place anyways when you split lists. I vote leave it alone. it ain't broken, lets not 'fix' it.