Ghazghkull Thraka is an alright choice, however, he will slow the squad he joins down since he's slogging and he's Slow and purposeful. And he's a lot of points that could be used for more boyz.
Drop the armor on the ard boyz. It's a waste of points that may as well just be used on more boyz. Also, you need more boyz if you're running straight up horde. Base of 70 boyz in 1500 points? Swap Ghazghkull Thraka for another KFF, drop armor on that boyz squad, and take more boyz with those points. Then I would recommend getting lootas so you have some semblance of support for your army, since your boyz will just get mowed down by Eldar and Dark Eldar if you don't kill their tanks. Also, drop the Nobz, they're pretty much a waste of points with the way you've kitted them out, and you may as well get more boyz or lootas for their points.