eh there is quite a lot of Dragon symbolism IRL in various cultures and i'm pretty sure Dragons were (sadly) mythical IRL...
they feature heavily in heraldry and some places even have them on their flags: http://commons.wikimedia.org/wiki/Category:Flags_with_dragons
then there's stuff like this: http://www.lore-and-saga.co.uk/assets/images/Stormy_Fiord_300w.jpg and this http://odinsvolk.ca/dragon.htm and this http://www.fylderamblers.org.uk/walkingholidaysimages/norway/10thsaturday/49stavechurch.jpg which tbh is where the whole Nord dragon decorating theme comes from...
and yes those are stylized dragon heads on the roof ends of a church in the third pic. funny how that building could almost be in game huh ?

point being if we had it IRL and no real dragons it seems perfectly fine that they would when there was...if you see what i mean...