I think there's two ways to look at this:
1) you can make STH the fastest on your team. His taunt provides a 30% TM boost which can allow your entire team to go before theirs. However, it risks him being dispelled almost immediately
2) You can pair him up with a much faster tank, like Poe. Poe taunts, gets dispelled, and then STH taunts. Now they have to focus fire on STH, which gives you more TM throughout the match. By the time his taunt runs out or gets dispelled, your other tank can start his taunt. However, this setup is neutralized by someone like B2 or Sun Fac and it may risk him getting ability blocked first.