Now and then, a questioner will be given the advice in comments that his/her question would be more appropriate at another SE site (say, a question about LaTeX would fare better at tex.sx than at stackoverflow). Sometimes, the questioner will then proceed to ask a carbon copy of the same question at the site he/she was pointed to. A few hours later, the former question is migrated. The target site now features two questions that are literally the same (perhaps with the exception of tags).
I'm aware that the consensus for "normal" duplicate questions (those with different wording) is that they should only be closed, not deleted. But does this also apply to "literal duplicates"? Is there any gain to be had from keeping them around (although closed), or can/should they be deleted to keep the (migration-target) site tidy?