Throwing knives are what you need.
The Hellsing is far better and you can pick one up from the very end of Dead City 2 as well, it makes the entire section of the game until you get to Polis infinitely easier.
As has been said stealth is very possible, it's what I do when I play through that section, it just requires patience and knowing where all the enemies are.
The only hard part is the group of 3 sitting around a table. Either completely ignore them or leave them till last and lob a grenade at them.
The way I do it is this, start in the tunnel you come drop down in, head up and a sequence will start which ends with an enemy running down the way you came, hide behind some boxes and kill him as he runs.
Next head back down the middle tunnel away from the rat race guys and head to the opposite side of the station from where you came in, there is a guy sitting down, easy kill.
Next get on to the tracks and go under the 3 guys talking. you will come out in the middle of the station with 2 guys talking by a door, simply wait for them to stop talking and then slowly move towards the guy in front of you, he will die automatically. After this hit the switch on your left and continue past the dead guy, turn left avoiding the trap and take down the guy the first guy we killed was talking to, he's sitting on a sofa.
Next take out the guy who was talking to the guy who gets killed automatically, he will usually be in an alcove opposite the guy on the sofa you just killed, if he's not there just wait for him to be. Finally kill the two guys in the center racing rats, this is a lot easier than in sounds, just take out one then the other quickly and they won't be alerted.
Finally there is a guy above the door next to the rat race pen, he's behind the bright light so he can be hard to spot. Once he's dead head up he ladder. There is a guy outside the little box room you end up in, just listen and wait for him to pass the door then knife/Hellsing him in the back.
Now you are past the hard part, you can either continue stealth or go guns blazing from the little walkway you are on, you have lots of cover and there are only about 5 bad guys. Alternatively just continue stealth killing however this section is much more difficult to stealth without the Hellsing.
Yes I have a very good memory for games.