That Skarmory doesn't always opt to Roar, as I see DP used very often. So unless it's been Skarmory3 (645) most of those times, I've been "lucky" enough to have the one with Roar actually use DP futilely as I 3HKO with Crunch.
I've been Roared before, but only if Skarmory1 (373) is the second poke do I actually care. As poke three I just SD with Chomp and fire away with OR on a Skarmory without recovery. If it Roars as poke two I am going to Charm then try Flash with Mesprit in spite of the 50% Keen Eye chance so it can't start shuffling. I'd want to get Chomp a Sub and one SD, as Outrage will always 2HKO Skarm given prior Crunch damage.
Most importantly, Acupressure boosts Evasion too. Skarm has only two chances to Roar Drapion that 3HKOs with +6 Crunch even if Roar is tried. And the fewest number of trainers use Set 1 pokemon compared to any other set (only two of 100 specialize in Set 1), so being Roared away by Skarmory1 is a very remote threat.