If a car was parked and another car pushed it a couple of yards could this cause same damage to the drivetrain?

Come on, you know the answer to this. The person driving the car that caused the damage to the two parked cars is responsible for all damage. Who else would be at fault? Accept responsibility for your actions.

your car is parked unless you have someway or another had the car in drive while you weren't in it then how can you pay for damages you did not incur and if you weren't parked in a no parking zone or a handicap spot then the person who hit you is responsible for all damages because they weren't paying any attention

Yes. You are responsible for parking your vehicle in a way that damage will not be caused to another's vehicle. So say you park on a hill and the vehicle rolls back and hits another vehicle, you are liable.

Typically the driver that hit the parked car. But if there is no record and was a hit and run, you file a police report and your insurance should coverthe damage, less deductable.

Generally speaking, the driver in motion is considered to be at fault when a parked car is hit, even if the car was parked illegally. The exception to this would be if the car was parked in a dangerous, hard-to-see location and the driver in motion could not have reasonably avoided hitting it. For example, if a car is parked on a sharp curve in the travel lane of a narrow road, and the driver of a car driving around the curve at the speed limit would not be able to see the parked car until too close to it to avoid a collision, then the driver might not be liable for damage to the parked car, and indeed the driver who parked the car might be liable for damage to the car that hit it.