Yes I had previously done that calculation as well. The only thing I can think of is if you are (or maybe your employer is) already paying for a rack that is underutilized power-wise but has a little space left you can add a few of the miners.
What sort of servers are used that have higher densities of power than the usual rack? (fitting with the scenario you suggested above).
The situation I described would have
lower power density. Thus it would have excess power that could be balanced closer up to power density limits by putting some miners in the rack. An example would be servers that are usually idle, or large storage arrays. One might even speculate that "the Israelis" (I can't manage to get myself to memorize their name) have such a scenario in mind for their hosting produce, or a major customer who does.