RE: 8231s on ailerons
It may be possible to do that, but it will take much care with mechanical set up if using a Y to connect the servos. You will need to adjust the mechanical set up (matching the servos together that center and throw the same, distance out on the control horn, distance out on the servo arm, and pushrod legth) such that there is no binding between the servos. An amp meter in line such as HAN172 will help set it up properly.