I have gyros on both rudder and ailerons (2x Futaba GY351). First few flights only with gyro on the rudder, and it flew very nicely. In windy conditions, I did not like the way the wings were "rocking".... It took away the scale apperance. Gyro on the ailerons fixed that beautifully, and now I love flying my MIG in windy conditions as well
So, you do not need gyro(s), but I would recommend at least one on the rudder.
Kim