Urho is so much much more than Ogre3D and it's definitely not a clone of Ogre3D. It's full game engine with a lot of features - audio, physics, navigation, ... while Ogre is basically just rendering library. And Urho's rendering is not closer to Ogre than any other rendering solution out there. The only thing they seem to have in common is that people are slowly losing interest in them, which is unfortunate.
