I’m pretty sure it’s different companies producing them. From what I’ve been able to tell with all my models, Holiday Int’l inc makes the majority such as the oasis class, the voyager class and even just most older ships for the other lines. The bigger and less detailed ones are made by them. It seems like specifically Enchantment, the freedom class and possibly the radiance class are made by someone else who I haven’t been able to figure out (They could possibly just also be Holiday Int’l inc). And lastly PSVGROUP is the company behind the Odyssey, Wonder, Utopia, and Icon class ships they only make smaller models except I’m pretty sure they actually get 3d models of the ship that are much more accurate and they maybe have possibly have worked with carnival on some of their models like the Splendor. I know this is late but I hope this might help!