Thank you so much for the reply.
By Nandroid you mean an Android backup? Or is "Nandroid the technical term for Android backup?
So , let's say I do the first experiment, I already have ClockWorkMod on an Android phone, can I still use it on another Android?
If yes, how would you manage to get the download to the other phone please?
Now if I manage to get ClocWorkMod on the first of the 13 Galaxy note 2 devices, I do the first backup on a Micro SD card, am I right?, then what do I do next? How can I move the backup to the next of the 13 Android phone?