I played with a LOT of dolls of different sizes growing up, and I had no problem getting them to interact together in their worlds. I mean, the barbies and the plastic dinosaurs were BEST FRIENDS.

Heehee, maybe this is a thing! Barbies, Ninja Turtles, and rubber snakes were all standard features of the games I played, and the size differences... I guess didn't even register, or got handwaved with "April O'Neill is actually really short" and/or "they're MAGIC snakes". :D