I'm 174cm as well, but was eyeballing a Large / 520.  It's geo most resembles my current Madone, with the exception of stack being about 15mm low.  That can be solved with spacers, can't it?

Incidentally, a buddy of mine bought an actual Dogma, and said that they run small.  He replaced a 57 Orbea with a 59.5 Pinarello