I have a better idea(that I will just make into a modmod either way). We introduce the power grid system. All 4 plants require the Electric Power building which is only supplied by a national wonder: Power Grid constructed in the Capital first. The Power Grid provides an Electric Power building in all cities. If an enemy captures a city with an Electric Power with no Power Grid in their Capital, then they can build plants, but they still need the power grid(the power grid comes before these plants become available anyway).
Electric Power: 2 Specialists do not contribute to Urbanization Unhappiness. Receive +1 Production from the Power Grid. Receive % Production Bonus from Nuclear/Wind/Hydro/Solar Plants.
Now here's the fun part, these four plants are still mutually exclusive, but can now contribute to a national power grid. So you don't get penalized for not building the right plant, you get rewarded for trying to power your nation instead.
So if you have 4 cities that have nuclear plants built, they can provide +16% Production to every city.
I figured why don't we just make a strategic resource icon and have it hover over all the strategic resources to save space. I think that would fix a majority of the problem. I don't think anyone actually hover the resource to check which city has unimproved resources.