However, the Preds COULD BE more easily added into the Alien horror verse over the Aliens being added to the Predator macho verse.
I think this is where the issue so far has lied in most of the AvPs. You take the frightening out of the Alien and you lose, but if you ADD the horror into the Pred, you don't lose.
Best example I've seen so far is Psykore's FEAR 3. Where the main horror boss of the game was surprisingly a Pred where there was no super macho guy around to kill it. Just victims trying to survive it.