This is a year old, but I'd like to voice my support for moving "Search With [...]" after lookup items (that is, in its own section after "Look Up [...]" and "Translate [...]". The context menu in macOS is designed where users can move their cursor one point on the trailing edge to highlight the relevant item. This makes selection very sensitive since the first item should naturally be the most common action. While a web browser is (mostly) about searching, for selected text in general, the most common action is to look up information about the term (hence, why "Look Up [...]" is the first item in most apps dealing with text).
In particular, Search With is more expensive in terms of user focus than Look Up or Translate is. When a user selects "Look Up [...]" or "Translate [...]", the text is highlighted and a popover appears. When a user selects "Search With [...]", meanwhile, a new tab appears and is switched to. Undoing the former requires escaping or clicking outside the popover, while the latter requires switching or closing the tab (either via the button or shortcut). The point is, there's a significant overhead to searching compared to looking up, and so making it the first item when Look Up can serve a subset of its purpose well makes for unnecessary stress.
If the menu was, instead, arranged like so:
Look Up "..."
Translate "..."
- - - - - - - - -
Search With ...
- - - - - - - - -
...
Not only would this restore user intuition, but it would also make searching a more clear action (since you'd need to move your cursor more to highlight it). I personally tried having Look Up not be the first item in an app of mine and came to the conclusion that having it first is simply superior.