OK. Have fun. Hope it goes well!
You won't be idle for a long while
i'm struggling to remember any update I ever made to a front end that didn't also involve some type of alteration to the back end.
Even just a minor tweak to a table is going to force you to manually update each and every back end.
It is certainly easier to maintain one back end and automate updating of multiple front ends.
Another thing to consider is periodic backups of the data. Its much simpler to make a backup of a single back end than several.
I would certainly advise that you make it crystal clear to those involved in that discussion of the potential pitfalls in that approach especially if it is your name thats going on the project.Unfortunately, this has already been discussed and because of the nature of our work the system has to be split in this manner.