There aren't that many of the phrases you refer to and they aren't actually used in a way where a phrase group would be useful. They aren't the phrases that are used in the code.
I presume you have actually noticed it triggering queries to load individual phrases when looking at the moderation actions (delete_posts, merge_posts, etc). That's actually a separate bug -- in this instance, it relates to phrases not being preloaded correctly if they contain "..." in the name (or some of our other phrase modifiers). I am investigating that now.
However generally speaking, for rarely hit pages, we're not overly concerned if there are a few phrase hits. The benefit of making major changes to avoid that is likely to be heavily outweighed by the development time it takes.