Thanks Monsterzonk. No, don't think I'll add feathers. I've even thought about transplanting the tribe to the eastern steppes (north of the Mountains of Mourn), as that would make the inclusion of my mortal troops more likely, and the beastmen can still look the same.
I played another game against the Lizardmen of my friend today, and had a blast.
In this shot my big herd has stood the charge from his saurus cavalry, and my knights are ready to slam into their flank:
It was very bloody, after turn five he didn't have anything left on the table. I still had my Chosen Undivided Knights, one out of ten Khorngors, my general and the standardbearer and one ungor from my biggest herd. The stars of my army were yet again may Khorngors, they took out about 650 of his points, and the armies were 1300 p to start with, so that's half his army.
He has bought a new gaming mat and some hills, so this was the first time it really looked like a proper gaming table with nice terrain and two mostly painted armies.