Outrage and Dragon Dance aren't available to Overconfidence Salamence (iirc).
On top of that, Intimidate is far more reliable. Have fun switching into Lucario as he Swords Dances without it. Now Scizor is doing even more to you with CB U-turn, etc, etc. Intimidate is guaranteed to do something, and you can abuse it multiple times to stop a threatening sweeper. Overconfidence gives you an extra attack boost (which it really doesn't need) and they can still revenge kill you with Bullet Punch or Ice Shard. Oh yeah, did I mention a Salamence that has knocked out a Pokemon's Dragon Claw is the same power as a +0 Salamence's Outrage? This ability is extremely overhyped, IMO.