You need a spot for Moore and I say he duplicates morse much easier than LaRoche, who hits left.
Moore basically IS Morse: plays first or left about the same, runs about the same, has similar power numbers wherever he has played. You can afford to lose Morse, but not ALR.
I realize Morse is signed for another year and LaRoche isn't, so I am assuming a reasonable contract is worked out for one and a trade worked out for the other. If not, too bad for both the Nats and ALR.