j4s,
Welcome to the forums! I think this is a great idea. I've used (and am using) Bret MaA as a base for Empire halberds. The key is to make sure their weapons are uniform and their heads are Empire heads. That goes a REALLY long ways to making them look army-appropriate.
It should be noted that the arms on those models are funky, though, and you'll probably have to use side-cutters to chop off the upper arm which is attached to the body. This isn't so bad, but you may have to green-stuff the parts not covered by the new arms. I think they look good with the cut, however, and it is easier than trying to get the right proportional cut by trimming an arm down to just the fore-arm (in my opinion).
Finally, this might be a better topic for the Brush and Palette forum. Even so, we're happy you're here! Good luck, and take pictures.
