I want to attach multiple servos to Arduino but all them must receive same command. If it possible to connect all servos to one command pin (I don't want to use "for" in code to minimize processor time for operation)?
IMHO it is possible to connect more than one server PWM control inputs to a Arduino output pin.
The Servo input is something like a comparator with an very high resistance. So the servos should not influence each other in any way, nor will the output pin be overloaded.
Because of the input capacities of the servos, there might be a limit of the count of the servos.
And if you supply the servos with power from the arduino then, there is of cause a limit.
It is always a good idea to use buffers in a servo control circuit, to keep a sharp square wave signal. Parasitic capacities can reshape the signal even to a sinus signal.
That might confuse the servo control unit which works well only with a square wave (i.e a PWM-Signal).