The statement that the servos are not powered through the receiver is not quite true. The normal setup is that the battery is connected to a bus in the receiver (all center pins connected together and all ground pins connected together) so all the power does have to go through the receiver. Depending on the thickness of the copper traces --is it 2 oz or 1 oz copper) and their width, there is a current limit. This will normally allow in excess of 5 amperes without burning out so usually no problem other than voltage drop through the connections if they get dirty or corroded. Those that use high powered servos generally set up a seperate power bus for the servos which does not pass current through the receiver.