If I have 500 physic and 1,000 society and 500 engineering.
Building 5 tier 3 labs will yield 160 equally across all 3 fields (5 labs * 8 research jobs * 4 base research yield assuming no modifier boost as that can skew the result if I bring in other jobs that yield society).
Increasing society by 160 will yield only a modest 16% boost in speed which devalue the more society research points you have.
Compared to 32% boost in speed for both physic and engineering. Having a huge slant in society actually make me want less of it because of diminishing return after a certain threshold.
160/1000 = 16%
Doing a 10,000 research cost at 1000 will take 10 months. 1160 will only save you a month or two at the most rounded up.
160/500 = 32%
Doing a 10,000 research cost at 500 will take 20 months. But at 660 it will save you 4 months or 5 months rounded up.
This just means that the more society research points you have; the less valuable next point will be in terms of saving you time on research at some certain threshold.
This is why I want to be able to shift my research jobs focus because society is the least useful number to push out of all 3 fields due to having so many secondary sources plus the research job itself.