Yes, you can most definitely drop Gandalf support, without a deck, their cold to your shadow anyway, so they won't be able to double and stop YOU from doubling. Just make sure your shadow CAN get the job done AFTER discarding their deck, at least gumming up the board for a turn where you can seize the initiative. Also, notice that, strategy-wise, it's much more difficult to sculpt a Shadow hand when the other guy is meessing with your draw deck, so most people, once they realize what they're up against, will try and run, which means your White Arrows of Lorien WILL hit a lot of Shadow cards if you don't give them a lot of twilight to cycle their hand (and also means you'll need to be able to race behind them, so you can swap ahead in a single turn when they're left cardless). And if you DO give them that much twilight, then their deck will run out that much faster. If you can then start Gimli, like ket suggested, you can devote some space for burden removal (not that corruption will be that much of a problem, since as I said, they'll most likely ditch shadow cards and you will also hit some of them with your shadow).