You are having a busy time posting on here!!
As you understand, if the weight of the motor before and after rewinding is the same the weight of copper will be the same.
As you say if the Resistance of each phase is the same, there should be the same amount of Copper in each, unless of course one phase has a short length of small diameter copper and another phase has a long length of larger diameter of copper, which could both give the same resistance reading!!
You can also check the running current in each phase and you would also check the temperature that the motor is running at when you tested it.
The efficiency of the motor is linked to the ratio between the resistive losses and the Inductive losses.
It is always better to ask a stupid question than to do a stupid thing.