In many cases, questions will be tagged with both a specific tag and a general tag. For example, network-interface and interface on a question dealing with network interfacing. Both tags are undefined. network-interface is unambiguous but interface covers a lot more territory.
If all network interface questions use only the network-interface tag, it would reduce the diversity of meaning under the [network] tag. It could be that the remaining meanings are sufficiently similar that grouping them under an umbrella tag is fine.
This post, tag-tag-version-or-just-tag-version, indicates that as a general rule, the generic tag should be removed if a specific tag is appropriate. When I see examples, should I just go ahead and fix the tag or is this something that should be posted here for review?