Does it really matter whether the formation is simmetrycal? I can't exactly prove it, but I don't see why a formation would be in disadvantage just because you aren't using the perfect looking lineup. For instance, I've been playing a rather peculiar formation with an AML and AMC, since I still haven't got my hands on a decend AMR. My formation is this:
And it works great, just like the narrow diamond 4-1-2-1-2, with the advantage of having a winger on the left side. Opinions?