How do you figure? This would be true if they have a machamp already set up.
The main fail for Machamp is that Regirock no longer exist to help it supply discarded Fighting Energy, MagneGatr can easily use energy switch and draw a lot of cards to do 150 damage, but Machamp on the other hand, needs to wait until they gather enough energy cards, not to mention the big dependance of DCE, reducing its attack chances to only 4, and the big hit requires not 3 but 4 energies to do 100>150 damage... And if Machamp goes, all the energy goes down with it, getting enough rare candy and evolutions at the same time you build up your attacks and survive the storming of Lost Burn, is gonna be a medal worthy war prowess.
Do they allow you to take 2 prize cards in 1 turn?
RDL may take 2 prize cards out of almost anything, but DCE+Bouffalant+Revive can also do the same thing against RDL, since KO`ing that legend gives you 2 prize cards, the one with the prize advantages wins the slugfest, Add the fact that RDL is not easy to bring back from the discard pile, and doing so requires an extra turn to attach rescue energy instead of the orthodox lightning, giving the opponent time to rise the prize advantage. Teching Bouffalant and Alomomola with Energy Switch in a MagneGatr deck is a wise choice, 90 damage can easily take care of a 40 damaged Zekrom, hunt Donphans, Emboar or Reshirams without risking the suppliers, snipes with SEL and fulminates anything else with Zone.
Zorark and Bouffalant wont even have a chance to attack RDL, because a good RDL player will only use RDL to take the last 2 prizes of the game, to win the game right then and there!! If you are attacking with RDL early on you are not using RDL the right way.
I agree that is an awesome game finisher, but is also an outstanding game opener, as well as a big nuisance to keep it in your hand that slows down Magnetic Draw, not to forget is a big waste of bench and a dangerously tempting heavy target for Pokemon Reversal.
My conlcusion is that MagneGatr/SEL can beat MagneBoar/RDL without risks or Yami-YuGi plays, MagneBoar on the the hand, needs a really good strategy to pull out the victory, they have the same speed and hit heavily, but one discards a lot of energy with stage 2 while the other hits using basics without drawbacks, anyhow both lose horribly if they get prevented from using trainer-item cards.