The only way to have the exact same travel at any given time on two servos is to have either a new generation radio or a JR Matchbox, if you have two use a radio mix to use two servos you can actually adjust the sub trim and EPA or ATV to center and match de travel on both servos, but if you lok closely, as the servos moves one will get to the end point before the other, then this has to be corrected on the mix so the slow servo can match the fast.

This slow servo, is not actually slower, but the servos moves in sequence, so the elevator will be the second to move and the aux elev will be the seventh (AUX 2), on the new radios this is not the case, 12MZ,14MZ, 12X, ie.

On the match box you can adjust the independent EPA and SUBtrim, but there is only one single input signal coming from the receiver, so this speed problem goes away.

In two servo application this is the all the choices and only choices to make it work.

Regards