Let's get straight to the point. Kentrosaurus is going to be a cut above. It's piercing gaze alone will be enough to send even the largest carnivores running. It will slash the competition. Tribes would be foolish not to stick this in their arsenal. It may be a hard tame, but I'll take a stab at it. Did I mention that it's pointy?
Awesome way of protecting your Brontos from Gigas in large scale raids. Make sure you have set to a low follow distance and it will cause the Giga to enrage if it attacks the Bronto, throwing the rider off and hopefully leaving the Giga to be at your mercy once it stops enraging.
These guys are the baine of most bosses due to their damage recoil. Breed a bunch of these and use for home defense or even boss fights. However, their low torpor makes them an unwise choice for the Broodmother. Don't repeat my mistake!