How should thumbnail unification tags be handled?

Currently, there seems to be inconsistent ways of handling tags that end with "サムネ統一" (thumbnail unification) and the rarer "サムネ不統一" (thumbnail disunification) regarding a particular source. Some examples:

1. 膳サムネ統一 is aliased to Zen.
2. 毛利小五郎死亡サムネ統一 is parented to 毛利小五郎死亡 and marked as a source.
3. 6月3日サムネ統一 is parented to Tokai Teio like above, but is marked as a meta tag.

Personally, I find thumbnail unification tags redundant, since I think having the same thumbnail across videos is a part of the source's charm, and it feels like viewers expect the thumbnail to be the same. If this is the case, such tags could be merged to the source or perhaps deprecated. It might be more notable when a work has a different thumbnail than expected, hence the thumbnail disunification tag.

However, I would like to hear thoughts about this. Is there value to thumbnail (dis)unification tag on the database? How should they be handled?