Jdfute

MS is rated under DC 8018 but only discusses the minimum rating of 30%. Obviously, to get to SMC M either you have other ratings above 50% or 100% which give you the "bump" permitted by §3.350(f)(3) or (4).
Needing A&A is a 100% rating in itself which got you to SMC L in the first place. 
Always understand, SMC is the least understood of all VA entitlements. I've had raters tell me they have tried for years to grasp it but never succeeded. That begs the question "So who did you turn to in order to figure it out?" This is why I end up litigating in this area more than any other. It's also one of the most lucrative for the Vets as SMC is paid once you can prove entitlement-even if it was years or decades ago.