Gothic Chess has the King in the center of the board with the Chancellor on 1 side and the Archbishop on the other. This is a very important difference. The piece distribution is smooth. There is 1 new pieces to the left of the king, 1 new piece to the right of the king, and the other chess material is where it belongs.  In Embassy, having the east-west mirror you mentioned makes a big difference also. The game is played "upside down", as the east-west mirror is reversing the color of your pieces. Clearly in chess you remember this is the case. Black is the east-west mirror of white. So, Embassy Chess has white playing as black on the queenside, and the lopsided distribution on the kingside. Why would you put both new pieces on just one side of the board?