Sorry, that was catty. But this is a silly conversation. Some people may not consider DC canon, but however you regard that last two, there's no question that Deadly Alliance, Deception and Armageddon are MK5, 6 and 7 respectively.
Yup. They even have a flash of it in Raiden's memories in 9, so I don't know how "non-canonical" it really is. Look, whether you want to look at it as MK8 or MK9, it's still not MK1 - that released in 1995. A sequel doesn't have to have the number in the title for it to still be considered by it's numerical order. Harry Potter doesn't have numbers in the titles, but if someone refers to book six, everyone still knows they're talking about Half-blood Prince. Indiana Jones 2 is obviously Temple of Doom. This is a silly argument and this'll be my last post. Watch some Sesame Street - it explains numbers pretty well for my son; maybe you can pick up something too.