Thats my backup plan. But in the thread I mentioned, someone explained the limitations doing this way. Here it is:
This way(using virtual axis) both physical axes are treated equally and programmed the same. Neither is the master. Also, with the _mcLatestCommand option, the servos have to be in the proper order (node number-wise) on EtherCAT. The master would need to be a lower EtherCAT node number. Doing it this way just removes any chance of getting that wrong.
It used to be that the performance would be better with this option due to the fact that if both servos were tuned the same, the following error to the master axis would be the same and the axes would achieve closer synchronization. However with the _mcLatestCommand option, both servos would get the exact same command if you geared them together without a virtual axis.
I was looking if it can be done in a better way.