late 2013 MacBook Pro board can be replaced with 2014 or 2015 board?

My late 2013 MacBook has too small memory. (4gb)

While I was looking for a way, I wondered if I could change the board and solve it. If it is the same A1502, I think the external case will be the same. (screw, usb port, etc..)

As far as I know, when dividing A1502's model into two categories: 2013-2014, 2015.

1. A. If I replace it with the 2015 main board, will it be possible to assemble it?
2. B. If it is impossible, would it be possible to replace it with a 2014 board?

According to the investigation, I heard that there are some problems.

1. Battery is different between 2013 and 2015, but current battery is 0%, so even if 2013 is used continuously or changed to 2015 or 2014, it needs to be exchanged.
2. There is no need for additional function of touchpad.