(MemphisMark @ Apr. 10 2007,22:30)
QUOTE
If you declare something as another thing (let's say Predators for Land Raiders) then all of your Preds are LRs, and that's it. You can't have another detachment of Preds and they be Preds. They would have to be LR's.
Actually, not to be a pain ( 
), but you CAN'T use your Predators as Land Raiders in a Space Marine army. That's in violation of the second bullet point in 6.2.1. If you have Predators, then you can use them as Predators. The Counts As rule isn't there to allow you to designate one type of Space Marine unit as another - which, frankly, would be unacceptably confusing. I've had games like that ("Whoops, right, I forgot your guardians were dire avengers. And your dire avengers are fire dragons. Hang on, what were your fire dragons again?")
On the other hand, if you are making a Space Wolf army based on the Codex Marines list (fair enough for a tournament). You have some Leman Russ models for your Space Wolves (entirely in character), and you are trying to put them in the list. You could make them Land Raiders or Predators - either would be fair enough given the weapon loadout/toughness of a Russ. But if you decide that your Leman Russ are Land Raiders, then you have to stick to that, you can't have some Russ as Land Raiders and others as Predators.
