I mean mechanical hard drives shouldn't fail just because of a power failure. Unless the drive was just one power cycle away from a failure anyway. Or there was an associated power surge (but that could affect a lot more than the drives).
I think the biggest limitation for the number of VMs you can run has been the amount of memory you have for a long time now. But with 128GB you should be able to run a bunch. Not all that many years ago when limited to a 32-bit OS and 4GB of RAM it was a lot more limiting. But so much has changed since then.