I mean.... Have my take on this. (Note I personally would do this if 100% efficiency was my goal, though I plan on doing something else that is a little psychotic).
Wars ->
First Priority into Offence, (T5 Tanks, T5 Planes, T5 Ships (Only if Superiority rework goes live, else Infantry).
Second into Defence, (T5 Tanks, T5 Planes).
Third into Universal, (T5 Planes, T1 Spies).
Fourth into Econ, (T3 Revenue).
No war - below 1650 Infra ->
First Priority into Econ, (T5 Resource, T5 Resource, T5 Resource).
Second into Offence, (T5 Planes, T5 Ships).
Third into Universal, (T5 Land and Infra, T1 Spies).
Fourth into Defence, (T3 Planes).
No war - Above 1650 Infra ->
First Priority into Econ, (T5 Revenue, T5 Resource, T5 Resource).
Second into Offence, (T5 Planes, T5 Ships).
Third into Universal, (T5 Land and Infra, T1 Spies).
Fourth into Defence, (T3 Planes).
No war - Above 4.5k-5.5k Land Per City ->
First Priority into Econ, (T5 Revenue, T5 Food, T5 Resource).
Second into Offence, (T5 Planes, T5 Ships).
Third into Universal, (T5 Land and Infra, T1 Spies).
Fourth into Defence, (T3 Planes).
Edit:
I guess you could make a build with Econ/War quick switchable as well. But even then....