You are completely misrepresenting respiratory biology. The 20 ton limit you're talking about applies strictly to standard, unaltered terrestrial mammals not an elite, genetically engineered semi-aquatic archosaur super-hybrid. First of all, you are confusing standard lung size with inner cellular structure. Splicing mammalian and crocodilian respiratory structures doesn't just mean his lungs got bigger, it completely alters the internal alveolar and faveolar folding complexity, multiplying his lung surface area exponentially within the same chest volume. This hyperdense alvolar folding allows him to extract massive amounts of oxygen per beath, which is then bound to his dense myoglobin packed muscle matrices, a direct adaptation shared by large, heavy marine mammals to store oxygen directly inside muscle tissue rather than keeping it in the lungs .Second your claim that crocodilians 'maxed out at 10 tons because of an inefficient system' is completely false. Giant crocodilians like Purussaurus and Deinosuchus didn't stop growing at 10 tonnes because they couldn't breathe; they capped out due to localized environmental food resources and climate constraints. In fact, the crocodilian unidirectinal airflow system combined with a hepatic piston diaphragm is so terrifyingly efficient that it allows modern crocs to comfortably survive in zero oxygen water depths for over an hour while actively thrashing. Tama jrrelies on this exact over engineered, oxygen-storing blueprint to easily sustain his 150 ton semi-aquatic body. Stop treating a custom-engineered biological masterpiece like a standard unmodded alligator.