min min, I will face a ferrothorn any day of the week. Dragonite sets up on it 90% of the time, and I don't mean to sound cocky, but they have to outpredict me to get a t-wave off and that just doesn't happen. normally the routine is, they sr, nite comes in, I sub, they t-wave or leech seed, i roost gyro doesn't break sup. then i dd, and stall the next 7 gyros with sub-roost patterns. :) focus blast from tornadus is also a OHKO and Hurricane does like 70%, reversal from duggy also does a big amount of damage. it's not a big thread once you face it, however on paper it may seem so.
When I see CM Latias, normally i perish song, then when it comes back in to set up, i bring in dnite, i can normally survive a dpulse at 90% at +1 but i try to always have multi scale so i can dd and then kill it. If tornadus is in, Hurricane can 2hko at +1 and it shrugs off a dpulse as well. I haven't had much trouble w/ cm latias. another pokemon that looks dangerous on paper.
also, 4 RBY pokes: ballin? i think so