Breadboard to connect all servos in parallel for external power
I re-read your original post and thought I would comment on this.
Using a breadboard to power servos will work for tests with unloaded servos - servos with nothing attached to the output arms.
But if the servos are connected to something they actually have to work at to move, the breadboard will not be able to provide the current that multiple servos will demand, and may burn out a trace.
Use a breadboard for testing unloaded servos.
Use better power connections for actually moving things with servos.