Okay, here are some...things you need to know about teh bestiary.
If something has more then 10 HP, only heavy weapons are able to harm them. If something has a - infront of their health value, only EXTREMELY powerful weapons can harm them.
Okay, and a ground rule, Daemons and Possessed are NOT fluffy...
Another rule: Nobody can kill a Tank or Vehicle in one shot unless they are using extremely powerful weapons, i don't want to see people walking up to a tank, slapping it, and saying it exploded, thats god modding.
Here is the one that'll put you leaders in your places. The Stronger an NPC unit is, the less of them you can have.
In a defense, you can have an absolutely MASSIVE army, for defensive purposes.