Regarding Model A, I totally agree:
It is almost a MM clone, it does not add anything to MM, so 0% MMC. OK
Regarding Model B:
You say it is completely uncorrelated with MM, but you give numbers that shows perfect correlation:
MM CORR = -1% ==> Model B CORR = -1%
MM CORR = 1% ==> Model B CORR = 1%
If you use this numbers:
MM CORR = -1% ==> Model B CORR = -1%
MM CORR = 1% ==> Model B CORR = -1%
you get MMC = -1%, as it should be, because its contribution is negative to the MM performance.
Regarding originality:
You can do something very original and very bad, or something very original and very good. In your example, B is an original and bad model. Originality should pays if it contributes in the right direction.