"compare with that of" is both correct and usable in written English. You can use it when you want to compare something to another thing. For example: "The popularity of this movie was quite low compared with that of its predecessor.".
Moreover, relaxing Assumption 1 would make our analysis quite different from, and difficult to compare with, that of RS.
How did it compare with that of his parents?
How does your experience compare with that of Sergeant Harris?
Its influence, however, does not compare with that of Sanskrit.
How does the French obesity rate compare with that of the United States?
How does the success rate of these programs compare with that of traditional rehab clinics?
What does the manuscript reveal about Beethoven's creative process and how does it compare with that of Mozart?
Being a terminologist, I care about word choice. Ludwig simply helps me pick the best words for any translation. Five stars!
Maria Pia Montoro
Terminologist and Q/A Analyst @ Translation Centre for the Bodies of the European Union