Atropine is commonly used to treat other medical conditions. I would expect any modern emergency medical service to have it on hand (though perhaps not in the quantities necessary... we would need to use all the Atropine on multiple ambulances to treat one patient in this condition).
No, they essentially work to solve the same problem in different ways.
To use a very clumsy analogy, imagine nerve agents like VX are slamming on the brakes of your body. Atropine makes your body less sensitive to the effect of "brakes". 2-PAM takes the foot off the brake.