Careful when attempting to tame these. They may not be particularly good at anything when compared to other specialized dinos, but they do have two main things you should worry about. First is that they have to longest reach out of most any carnivores. They can reach you if you are on a rock, even if they can't climb up. They also have a stronger bit than a carno, but not as strong as an allo. The best strategy for solo taming is to be on a cliff, although they may run away. Another trick is that their turn radius is awful. So using a bow/crossbow/rifle you can just get right next to their body and keep turning with them in relative safety.
DO NOT listen to the person who wrote the following comment: “DO NOT tame in the lower south cave. It will get stuck on the way out and be trapped there forever.”. If it can’t (which will most likely be the case if tamed down there, because (in my experience) Sarcos struggle just entering the cave with how wide they are. But don’t listen to that guy. Just summon it out in the “Request Creature” tab and wait for it to teleport (I have summoned creatures out of the cave when they get stuck and they teleport just fine). Share this with anyone you know who struggles with that.
Just keep a slight distance away and shoot narco arrows into it's head. If you upgrade your movement speed some (idk how much exactly), you could just keep walking backwards to keep the sarco from reaching you since it never runs on land (at least none of them ever did for me).
I recommend taming one, they are super fast in the water, and they do a LOT of damage. I have tamed carnos and therizos but my one Sarco is the strongest one, I easily killed a megalodon and mine is only level 25, I only leveled up the stamina, speed and melee strength. Knocking it put is easy, just get it to follow you on land then throw some tranq arrows or darts to knock it out and feed it raw meat