A long burst from an assult rifle loaded with SnS does 13 stun damage, and half the Targets armor. Troll in heavy millspec? Likely going down to a glorified taser.
6+5=11, i dont know where you get the 13 from
But even with 2 net hits raising it to 13, the Troll has around 15 dice to resist meaning an avarage of 5 damage resisted, which means the first burst isn't likely to take that troll down meaning you need to shoot him again.
On the other hand a long burst of EX-EX has base damage of 12P, same 2 net hits raises that to 14 which is resisted with about 22 dice for an avarage of 7 damage resisted.
End result:
S&S: 8S with one long burst
EX-EX: 7S with one long burst
Using the second simple action to shoot a shrt burst with either ammo type takes down the Troll
The same troll would also go down on 2 shots from Defiance EX Shocker(wield a pair of them akimbo to get around the SS firemode)
So i fail to see the overpowerness of S&S.