Best Practise for deploying a 'clone' image across 200 android tablets (Samsung GT-P7510)
That is exactly what happens with the nandroid backup. You root, then do all installation of applications pre-stage, then remove the bloatware, remove all email accounts, then take nandroid backup. This becomes your gold ROM so to speak. It is stored in another partition of the master tablet. You need to move it to a removable SD or USB.

All rest of the 199 tablets will be rooted with TWRP/ClockworkMod, and then nandroid restored from the master image on the USB.

It is fugly, but until Acronis or Symantec come out with a tool, I am not sure how else do it. Clearly hardware companies have something that clones the disk.