Well ala you don't. I have run countless offensive teams without Jirachi or SpD Rotom-W, and Torn-T still wasn't an issue. Yeah it could kill one Pokemon usually, but then i would gain momentum and sometimes sweep with my CB Scizor / SD Scizor / Weavile / boosting Thund-T / SubSD Terrakion. Btw do you guys know that Torn-T is the perfect Pokemon to set-up against with SubSD Salac Berry Terrakion, one of the most dangerous sweepers in OU? Neither Hurricane nor Superpower can OHKO a healthy Terrakion, allowing you to set-up an SD and go to town as you are guaranteed to go to Salac Berry activation range. Of 'course you must do so after priority users are eliminated, but it still means that after every kill that Torn-T makes, Terrakion can threaten with a counter-sweep.
Part of the OU QC team, message
me for a check!