By clicking on the tags links, the user moves to a list of questions which are tagged by that specific tag and a list of related questions appears to him relatively. As an example, see the wiki of the reputation tag.
Do we need a list of related questions in the wiki of the tags?
I think this list of related questions is not only unnecessary, as the users have access to a complete list of related questions of the tag; but also it is harmful and misleading to the users and should be removed as the list may not include good questions which present the concept and use of the tag.
EDIT: A list of good examples of on- and off-topic questions on each tag does not have any harm, on the other hand, it really helps the users to know the tags and their usage better; but I think the list of exemplar questions on the tags can be harmful as we have them on the site right now. They are not well organized and reviewed. The list of the exemplar questions on the wiki of the tags may be harmful because:
As stated in this answer,
Some will be "bad" examples - usage that is wrong, or not necessarily wrong but not perfect either.; the user expects the sample questions be really on-topic and wants to learn from these sample questions about the sites policy on each tag; so, by reading wrong examples, they will be mislead and consequently;
From the usage perspective;
user will tag the newer questions wrongly;
user will do edits on questions and re-tag questions with the wrong concept;
by reading wrong examples and having wrong concept about the correct usage of the tags, and wrong usage of the tags, the user may face down-votes and major edits on his question and this is absolutely discouraging to some (not all) of the users.
From the maintenance perspective;
we should put extra time and effort to list the best and most on-topic questions in the wikis of the tags; if we don't pay enough attention to these lists, then we will not have good/working tags wikis at all;
choosing off-topic and on-topic questions for each tags needs some time and discussions between users, as we have not finished our edits on the tags of the questions yet, thinking and working on finding best lists for tag wikis will be waste of time;
reviewing the existing lists of exemplars in wikis needs another attention, who guaranties that the existing exemplars are well-chosen?