I wouldn't agree that Morris, Martin, and Leshoure are "interchangeable". You might feel that way, but I'll bet their owners do not.
I'd be willing to bet that the Martin owner in my league would trade for my Morris in a minute. And Leshoure looked good in his first week but was underwhelming in his second. Morris is on a tier above those two.
I'd rank them
10-team H2H non-PPR Yahoo league (qb,wr,wr, wr, rb, rb, te, k, dst)
QB: RG III, Romo
RB: McCoy, Matthews, Morris, LeShoure
WR: Fitzgerald, R. White, D. Thomas, Britt, L. Moore
TE: Hernandez, Bennett