I'd like to volunteer Twilight to stop Ryuunosuke and Peacock. With her level 70+ pokemon (not a full party of those, but as they include a Dragonite and a Kadabra she doesn't need numbers) and her level 4 Electric powers, she should serve as quite the roadblock. The thing is, she's going to put a very, very high priority in determining their identities, so she'll be doing everything she can to tear off their disguises, paralyze them for capture (hell-o Thunder Wave!) and basically just try to ruin their anonimity. Not saying she'll succeed, mind you, but expect clothing damage and maybe a forced retreat before she can unmask them. Also, she's a PGC member, so any features she notes about them will be sent to the Corps at large.

If that's all cool with you, then I think we might have ourselves a plan!