> the emitted power limits would be the same

Dumb question: If the limit is L, why do regulators care if I have one device with two radios each outputting L or if I have two devices each with one radio outputting L. Either way, total output is 2L.

What is the objective?

* To limit range? Then regulators shouldn't care about 2 radios in one device outputting L, as long as one radio doesn't output 2L.

* To avoid cooking nearby electronics and people? How do they account for the unpredictable, theoretically limitless number of devices in an area? What about someone working in a cell phone store or passengers on a Tokyo train at rush hour? Do regulators just set L low enough that any realstic number of devices together is safe?