I just ran the numbers on this, looking at Temple Guard fighting different types of Dwarfs, but the results should be applicable to other rathers....
Also, the Dwarf Gyrocopter is considered a war machine in some respects, but not when it comes to poison: it's susceptible, as per the Dwarf FAQ.
I'm relatively new to the game, but all I do is fight a friend who has dwarves, so I have some experience dealing with war machines. Terradons...