the neck looks ao muscular because of the dewlap and as far as I know there are several measurements that give the maximum length estimated between 15 and 21 metres, so I chose the middle between both measurements.
Can you do a Carcharadontosaurus versus Spinosaurus? I've never seen a detailed visual of what it would be like to see the animals square off. The only one I have ever seen was in Planet Dinosaur, where the fight seen was only about 30 seconds long. Amazing detail on your images, would love to see what you come up with in the future. Let's hope they find more cool therapods, just for you to draw