I think that the first hint to his impending doom was the statement that he wanted ALL nodes running exactly the same software...
He could use I2C to have master assigned slave addresses, by controlled sequential startup of the slaves, as example. But, there is just too much sugar for a dime in what he says that he wants to do... Keep it simple and it will work better.
Best solution to multiple slaves is node dependent software, hardcoded addressing at the very least. Otherwise, WHY HAVE MULTIPLE SLAVES if they are all doung the same thing and calling home with the same names???