I would like to suggest Physically Defensive Poliwrath. Not only it resists both of Terrakion's STABs, but you also get a decent Scizor and rain check in general as well as a decent Tyranitar counter.
Poliwrath resists Fighting? Neither Water nor Fighting resists Fighting...

Sorry if I sound rude, but you should test some Pokemons before really bashing it stat-wise.
Poliwrath isn't a good OU Pokemon, I have tried it myself a few times. Even with Swift Swim on a Rain Dance (NOT Drizzle) team.

The most effective Terrakion check for me has been Gliscor, so I'm just gonna second the Gliscor recommendation on that one.