To easily KO a saber, use a longneck rifle(tranq dart) or use a normal bow(tranq arrow). With a fast mount, Make the saber fall in a trap atleast 4×4 foundations big and 1 wall tall with doorways. Shoot the saber with tranqs every 4-10 seconds till it sleeps. Sabers have fairly slow torpor drain so for a lvl 120 it will only take 250 narcotics when taming it woth meat. Once the taming proccess is done, let the saber naturally lvl up and upgrade its health to a comfortable amount and then upgrade a bit of weight and melee.
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.
When I was taming my sabertooth on mobile. I went to dead island, lured a sabertooth to the small island beneath the main dead island (sitting on a pelargonis), jumped down to the ground and started shooting it with my crossbow and tranq arrows. When it was down I placed wooden spiked walls around me, my pelargonis and the sabertooth. Then I just putted like 100 raw meat (I always have too much meat just in case) in it and fed it narcotic when needed. When it was tamed I got it into my raft and sailed home. Really safe taming.