Zen, nothing of the sort was shown in the film. In fact, if we go by the previous one, there's a strong implication that they only face Aliens as part of the ceremony, as opposed to regularly. The film showed Aliens which hardly ever bothered to defend themselves. It was nothing to do with the Predator's alleged skills. They were so weak and pointless, even the civilian human characters in this film seemed to have very little trouble, with one killing them with a handgun, which shouldn't have happened, as Gorman had once evidenced.