I killed one solo at lvl 12. Using a spear and water. Standing next to a body of water, I let it follow me out for a swim, while swimming after me i stabbed it with a spear until it died. I harvested it’s meat underwater.. did no damage to me while it was swimming. I’ve dealt with dilos and raptors in the same way. Make sure there’s nothing in the water that could eat you before trying this method.
If you stumble upon a pack of sabertooths, make sure you have a movement speed of atleast 120%. If you do, run like heck away if you don't have any ranged weapons. If you have a range weapon and have atleast 130% speed, run on top of a rock and shoot the sabre. They die very quickly from any weapon since they have a weak health build.