Original description:  
No, they are not all meant to be sharing the same scene at once, but I tried to make everyone approximately to scale.
 
Notes and observations:  
-Discord is not among the other key givers because he is in part I.
 
-Cheese Sandwich? Where would Mesozoic maniraptors get cheese? There may not be any Mesozoic mammals large enough to make milk farming profitable. Their “cheese” probably derives from plant-based sources instead.
 
-Many more clothing-clad maniraptors here than before. How do they get the wings through? That is a problem the pegasi on the original show also have, so I don’t feel guilty about not coming up with an explanation. (My guess, however, would be that the wing holes are very elastic and can accommodate a folded wing. A maniraptor can then spread the wing once the entire limb has made it through.)
 
-Tyrannosaurid-based Tirek has been independently depicted by Dalek-Kenn. He is not a true tyrannosaurid here, also combining traits from Nasutoceratops and dromaeosaurids. (So far as we know, he’s a fairly one-of-a-kind organism in-universe, having strong anatomical discrepancies with even his sibling, so I didn’t think it would make sense to base him entirely off a single real species.) I imagine that he recapitulates tyrannosauroid evolution as he grows stronger, his weaker forms more closely resembling smaller and more basal tyrannosauroids.
 
-Changelings are not maniraptors in this universe. Early in their evolutionary history, they infiltrated maniraptor societies and gained part of their sustenance off love energy, driving anatomical convergence with their hosts. Early changeling queens are thought to have masqueraded as maniraptor princesses to incite the reverence of isolated maniraptor populations and thus draw out even more love energy, a fairly successful enterprise prior to the rise of maniraptor civilizations and familiarity of the populace with individual princesses. Over time, they became more specialized in feeding off love and evolved the ability to further camouflage themselves with magic. Their fangs are used primarily in intraspecific contests rather than to process food, reserving their magic for use against predators and belligerent hosts.
 
-Breezies are the closest relatives to changelings that we know of in this universe. They do not closely resemble any contemporaneous maniraptors, but owing to their pollinating lifestyle they do bear a passing resemblance to some that we are familiar with: hummingbirds.
 
-The sirens are hesperornithine-like sea monsters that retain a typical archosaur tail as the primary source of propulsion in water. Their feet are used for steering and hauling themselves onto land.