JK_Daddy:
Here are the options I choose if attacked by slingers:
1) If 1-3 slingers walk into my town, I immediately send over my villagers (a dozen or so) and bone them to death.
2) If 4-10 slingers get close to my economy, I run my villagers and try to mass a bigger army of axers and slingers and engage them when I am on a hill.
3) Slingers are very vunerable to cavalry so if I am Bronzing and I have access to gold, I will get a cav/slinger army to go kill whatever mass of slingers my opponent has.
Remember that if you Tool late with even 8-10 more villagers, but your opponent has already massed a dozen or so Tool units and is very aggressive with them, you will probably lose.
Here is what I will never ever do:
1) Try to build an army of bowmen against upgraded slingers (even Assy and Hittite bowmen die).
2) Build towers.
3) Try to Bronze if I don't have access to a gold pile for cavalry.
I have been on the giving and receiving end of massed slinger armies (20+ slingers) and I know that slingers can overwhelm even Assy CA's if the massed army is sitting at the Assy archery ranges. Cavalry and Stone Throwers is really what puts an end to even the biggest mass of slingers.
Can you survive the Blitzkrieg?