Have 2 Mnks and let him do all the Dragon Kicks. Also, you have to take everything you read on the Internet with a grain of salt. Actually, make that a bucket of salts. One person made an analogy of DPS to one's dick size, people will always claim to be have a bigger dick than they actually have. Even if they post a screenshot, there can still be many problems with it, problems that I have listed far too many times so I won't do so again. The only way to truly access someone else's dps is to be there yourself and parse it yourself and even then you could be overlooking some factors.

I can tell you this though, 450+ dps is certainly not "common." Of all the ilv110 weapon Mnks I've seen, they only make 440-460 dps if they have another Mnk doing Dragon Kick, else they are around 420ish. T8 is such a stationary fight that as long you have know how to play the job, there are only so many things you can change in your rotation, very few of which will make much difference.