The wargs themselves don't usually die and the orc survive.. Usually its the other way around as if the orcs dead the warg usually ends up running away anyway. Plus im pretty sure orcs arent that much harder to kill. Pretty much if you win a fight always say you are going to wound the orc not the warg. So it should be pretty unlikely that you will end up with an orc with just a handweapon.

Have you ever played with wargs vs enemy archers? There's a 50/50 chance of that arrow hitting your warg instead and it's even easier to kill than a shielded orc provided it's a man bow shooting (same chance for elf bow). Last time I played with wargs, my captain and about two riders ended up getting their warg shot from under them. In fact, if I remember rightly, the captain lost his warg in close combat, when my savvy opponent elected to strike the warg instead, thus improving his chances of wounding and greatly reducing my captain's effectiveness. Against a hero with fate and multiple wounds it is often better to kill the mount first to level the playing field a bit. On top of this, you have a small chance to get a free Str3 hit if he rolls poorly on the thrown rider chart and he will then be prone!