At a previous company we had a 'farm' of test phones that we used for testing new versions of software. A large number of those test were 'stress testing' which

At a previous company we had a 'farm' of test phones that we used for testing new versions of software. A large number of those test were 'stress testing' which would probably be analogous to the sort of load you would have it they were to be treated as a 'datacenter'. Based on that I'm pretty sure that the biggest issue with managing the cluster would be the extremely high failure rate. That's not to say that this won't work because I haven't done the maths, but it kid a unique challenge.