Narrow diamond will almost always beat 4-5-1 V. His DL/DR counter your AML/AMR. His 2 DCs coounter your ST & 2 MCs counter your MCs. If he put red arrows on the DMC & AMC they would overpower your DMC together & His 2 ST face off against your 2 DCs.
To counter a Narrow Diamond formation try using 3-5-2 V (3n-1-2n-2w-2), 3-5-2 flat, or 3n-1-4-2. I know that on july Fourths counter formation table it says 4-5-1 V style counter the narrow diamond, but this is false.