DMC has the same set of key abilities as DC, plus Passing and Creativity. DMC is basically an extended version of DC judging by skills.
But we can't train flank positions to DMC after the update:
If we want to add DL or DR position to DMC we need to add DC first. And this is so much the same for DMC that there will be no new key abilities. This is not just illogical, but also unbalanced: DMC is kinda dead end comparing to other positions. Even ST has more options -- they can be trained as flank players without being AMC.
If you have merged DL with DML (and *R), then please be consistent and let DMC to be trained as DL/DR without useless step (DC) that gives him nothing new.
By the way, now we have impossible monsters like this one:
We can't train players like this, it's against current rules. But here he is!