Do they fit in a GW Empire-themed army? A Kings of War Bretonnian Army? They do look fantastic.
I think they would be a good fit for a Bretonnian force, especially if kitted out with the kettle hats and a great helm.
However, for an Empire-style force they would be rather lacking in the puff-and-slash department; that is something better served with The Assault Group range of halflings (originally commissioned by White Knight).