That's a gross oversimplification. They're not really hybridising in the traditional sense, which requires actual compatible chromosomes and sexual reroduction. Only very closely-related species can do this, like Horses and Zebras. Creatures from an entirely different evolutionary tree right down to the microbial level wouldn't have a hope, even if it looked similar.
Convergent evolution is a real thing that can result in totally unrelated creatures evolving the same traits because they're useful for survival. For example echidnas and hedgehogs look very similar at a glance, but they're from completely different families of mammals and evolved in totally separate parts of the world. For a more extreme example, wings have evolved in insects, mammals, birds and reptiles at different times throughout Earth's history. It's not at all impossible that a Predator would evolve traits similar to Earth organisms because they're useful in their environment or were at some point in their evolutionary past.
The Preds in The Predator are gene-editing themselves with characteristics taken from other creatures' genomes. It's not the same thing as hybridising and their superficial similarities to Earth organisms don't really mean squat.
Also, the film you're both drawing this argument from will probably be considered non-canon by everything that comes after it.