"Therefore it is clear that the sin of unbelief is greater than any sin that occurs in the perversion of morals." ST, II-II, Q. 10, A. 3, corpus.
In order for your opinion to hold, you must demonstrate that St. Thomas taught that murder is an essentially graver sin than sacrilege committed against Christ Himself in the Sacraments, that is, of something essentially supernatural. Pointing out that accidental culpability lessens subjective guilt is irrelevant when the discussion involves the essence of a thing.