Those aren't the problem. The real issue is that the tetrapods which evolved into most land animals (amphibians, reptiles, birds, mammals) are further down the

Those aren't the problem. The real issue is that the tetrapods which evolved into most land animals (amphibians, reptiles, birds, mammals) are further down the phylogenetic tree of bony fishes than coelacanths and lungfish, which are further down the tree than cartilaginous fishes like sharks and rays, which are further down the tree than jawless fishes like lampreys and hagfish. In taxonomy, it's called a "Paraphyletic group" [1]. [1]: https://en.wikipedia.org/wiki/Paraphyly#Examples https://en.wikipedia.org/wiki/Paraphyly#Examples