Not even! Haha I swear, it's a dream team for the E4.
Pidgeot's Wing attack kills Aaron's Beautifly. Garchomp's dig takes out his Drapion. Pidgeot's wing attack will sweep the rest of his team, usually all 1 hit KO's.
As for the second person, well, she's a bit harder. Just continually use Dragon Claw and Crunch with Garchomp, and her team will be slaughtered, leaving you with ample PP.
For the third guy, use Garchomp's Dig to get his Rapidash, Pidgeot's fly to take out his Infernape, then Garchomp's dig for everything else except for Drifloon, with which you use Crunch.
Lucian's whole team gets swept with Garchomp's crunch. Beautiful KO's, except for Bronzong, for whom you need to basically waste a lot of Crunch, Dragon Claw, and Dragon Rush. But be sure to save some.
Crunch should take out Cynthia's Spiritomb in one hit. Next she should send out Garchomp, who will hit first, using Dragon Rush. This will leave you with a bit of HP, but your Dragon Rush will knock out the other Garchomp in one hit. In fact, Garchomp's Dragon Rush sweeps pretty much this whole team except for Milotic. For Milotic, I used Pidgeot, using Fly over and over again. It was funny, because Milotic would use Ice Beam when I was in the air, and Mirror Coat when I landed, so it didn't get a hit on me.
But yeah! I highly recommend this duo ;D
Maybe toss in a Gengar with Destiny Bond for the troublesome pokes.
Pokemon Diamond - Friend Code: 1590 2247 4967 Name: Mitch