When you mount a riding horse, the rule is simple. You get your AS bonus and use the movement of the beast. All hits are assumed to be directed at the rider and you use his stats. When wounds comme to zero, you roll on the Whoa Boy! Table.
However, what happen when riding a more complex creature like the Gigantic spider from the Nemesis crown Forest Gobbos?
It would be stupid that the entire model is taken OOA with the single wound of its rider when the spider has 3 !!!.
Also, wich toughness to use?
And attacks? Do they fight as one creature (each with his own set of attacks) or they figh separatly so they can together Stun an ennemy and put it OOA right after ?
From now, I play that the whole model have the total wound of both. Each have is own set of attack separatly. But when you attack you use the same chart as ballistic to see wich one you try to hit. So if you hit the mount, it doesnt have an armor save (safe of a 6+ barding if it has one) and use his own toughness while if you hit the rider he uses his own stats.
Well.. I'm totally confused ?