I beat nearly all TF's that I play against on my main account.
Because I don't use my Q + W combo on TF's... I wait for them to use a Blue Card, dodge their easy-to-dodge WildCard's (smallest hitbox in the game), I then W behind his minion wave, Q-E, Ignite and he's usually dead.
TF is ridiculously squishy, and sucks at farming about as much as LB does. Last hitting under turrets isn't hard either.
ie. - Full HP caster minion, autoattack each one once, let the turret hit them, and they'll be left with one autoattack of hp. Boom, farming under a turret.
Once LB hits six, it's over for TF. All you have to do is wait for him to waste his Pick A Card, and then W, E, Q, R (By the time E ends, it will proc the second damage effect of R, copying Q).