I just had one stack of Ogre Chieftains, and one stack of Veteran Orcs.
No recruiting occurred. Is there a level limit? e.g. he will only recruit plain orcs or any other orc unit below 4? (Is there any other unit?).
Conversely, goblin shamans easily recruit goblins for me.
Also, I tried the orc veteran skill "scold" and I did not notice any increased damage for my goblins or my ogre chieftains.
Does anyone else know if this is the expected behavior?