Have 2 people. One person carry the sabertooth with the argy or if you want, quetz/wyvern. The other person tranqs it. The saber will stay still, allowing head shots with the right positions, both saber and the shooter. The saber will fall from the from being carried to the ground when unconscious. This way, you can tame the sabertooth in your base or where ever you want/need.
Easily knocked out when you use a bloa. When stuck shoot in head while you can and itll go down quickly. Tranq darts make the process quicker, but arrows will do the job just fine. They can be picked up and dropped into safe taming cages by argies to make this easy tame all the more easy.
Build a raft 3 tall with a dinosaur gate on 1 side and ramps leading up from one of the outsides... agros the Saber, run up the ramp and drop in... have doorway next to the dinos gate... once it's in run out and shoot it through the door way.. can't hit you and it can't get through the door... easy tame just don't drive off :P