These two "test" figures played a very important role in the creation of the Beastformers Checklist that's to be built. In order to have a proper checklist dimensions and proportions between all the Beasts are crucial. And that's where these two came in with Rubberneck Giraffe being the guiding figure length wise and Killer Carp (with it's weapon alongside it) was the guiding figure for the width. So the reason some Beasts are not optimized in the available frame size is caused by these two guiding figures and for the sake of the accuracy.