Solo tame is hard, use the flower method to aggro a tapajera into a trap, tame that, then saddle up sit on front seat whistle attack and stop and shoot , repeat untill it's down, then tame
You can tame an Argy, grapple it and while flying whistle it to attack the quetz. From there, you just shoot it with tranqs. That’s how we’ve always tamed ours starting off.