Guns in my Fantasy?! HERESY says my critics.

[Lucas]

He didn't state "guns made everything obsolete immediately". Although it took several hundred years before the firearm dominated the battlefield, they did eventually render other weaponry obsolete.

Unless you're writing historical fiction, these sorts of timelines can be altered any way you please. You may want to keep somewhat close to our real timeline, to maintain believability, but it certainly isn't required in fantasy.

There was rather a gradual transition. Early musketeers were extremely expensive units. In the year 1500 for example, the Spaniards could mobilise less than 100 men with firearms.

As for fantasy, it is stuck in medieval Europe. It is sadly a strange thing that a genre with such a name displays so little of what it is called. 90-95% of all fantasy is basically the same story with alterations. Even the environments are near identical.

The point however is the following: You can theoretically have firearms that are pretty crappy and still have medieval weapons like pikes, swords and similar.

Moreover, the 17th century is underutilised as an inspirational foundation for fantasy. Especially dark fantasy. The middle ages were bright and warm in comparison with the 17th century. The 17th century was the Little Ice Age, religious wars, alchemic secret societies, the formation of modern nation-states, mercenaries raping and burning their way through Europe, overcrowded, filthy cities and constant wars were entire generations were mowed down.

Just check this: http://en.wikipedia.org/wiki/Thirty_Years'_War