either kill one or both with a poison arrow (the cowards way and my choice of ng+) or just sprint up there with your shield up ready for battle, taking out the right one fast or pushing him away and run around the corner.
you can actually sprint all the way without getting hit once all you need to do is run after the last arrow hits a wall, and sprint up to the first part. catch your breath and do it again this time before running if you stand on the either right or left side of the square wall you will only be targeted by one arrow meaning if you have enough stam you can either block/roll it and then run or just stand behind the square wall and then try and run up.
but if your really tired of it, i would say do a poison arrow, at one of them or both. either from the first platform or the second, i dont thing you can hit the left one from the first platform, but you can run away from his arrows easier when there is only one.
another slightly stupid tactic is run up and then block shield on the right guy dont lock target rather turn the camera around so you can see when the left shoot then roll when he do to dodge or shield him while kicking the right of the ledge
but if you hate that part so much again use the poison arrow, take out your bow any bow, and zoom in aim slightly to the left of him and ajust the hight of the shot, until you hit him, then just poison him stand in cover and go get something to drink check back to see if he either is dead or need to be poisoned again. if you stand at the first platform behind the right front pillar i think you need to aim about the enemys size higher to hit him.
he can also hit you but just walk side to side to doge it, you dont even have to change your aim, the pillar will block the arrow