Historical fiction is extremely hard to write while keeping accurate to history. And when you deviate and throw something improbable or unlikely in for story or entertainment purposes, you get people nitpicking and complaining about it. Look at 300 as a prime example of this.
But: when you write about an (let's say) aquilonian mercenary, why not write about a french mercenary from 14th century? Or when writing a story with an afghuli background, why not write an adventure story that plays in 19th century in the Near East? An adventure with settlers and wild Picts? Write a frontier story.
That's what REH did, he just changed the names and exchanged guns with broadswords.
The most appealing aspect of the Hyborian Age as a setting is that very little is actually considered off limits. You can have medieval knights going head to head with classical hoplites (or any number of other combinations) without it being entirely implausible. I can use the Hyborian Age as a setting for various genres of stories, ranging from "historical" fiction to the totally unbelievable. The only things I personally consider off limits are things such as guns and cannons. The rest is fair game.
While admittedly there's a lot to learn about the Hyborian Age, it's a largely much easier setting to write in as it encourages creativity rather than restricts it with historical "guidelines".
Edited by Spartan198, 30 November 2009 - 11:28 AM.