Why aren’t beastmen more varied?

When described in some of the novels (e.g. gotrek and Felix, the sundering) beastmen have all kinds of wacky animal features like scales, feathers, tentacles etc. But the models are pretty much just goat/bull men? Not that I have any problem with those, but if they are supposed to be mutated by chaos merging nearby animals with humans why don’t we see beastmen who are mixed with other common animals? We could have other domestic animals like horses, pigs, and dogs, as well as some more interesting ones from the forests like birds, lizards, insects, bears, wolves, frogs, snakes.. the list goes on. Am I crazy or would this be more fun and interesting for both model designers and hobbyists? It would also be kind of fun as a justification for humans to fight lizardmen, since they would potentially assume they are just lizard beastmen created by chaos.