I’d suggest using a variable for common varied words such as ${he} or ${they}. Multireplace is fine but having to type it out every time has more chance of typos or other errors.
This is broadly how I do it:
Where there are bigger changes, I tend to use if/else blocks when writing as I personally find it more readable, and then change it to multireplace once I’ve finished the paragraph. (As mentioned you’ll only want to use multireplace if there isn’t a line break, though.)
This is one of the major reasons my Twine games are under 20,000 words or so. Best of luck bug squishing! 