"Slaves needed for Local Surplus" bonus doesnt stack (farmland + farming settlement)

[spotlight2001]

In v1.5
farmland: -2 slaves needed for local surplus
farming settlement: -5 slaves needed for local surplus

15 - 7 = 8 slaves needed per surplus

so with 16 slaves in v1.5 I have got 3 trade goods
in v2.0.3 I only get 2 trade goods. When I increase slaves to 20, I get 3 trade goods

So this is like farmland bonus doesnt stack to building bonus in v2.0.3

is this normal in v2.0.3?

 

[DC123456789]

Hover over the icon for the number of trade goods produced. Assuming you haven't integrated Sabellian culture, you're probably getting the +2 penalty for the territory having an Unintegrated Dominant Culture.

 

[spotlight2001]

Hover over the icon for the number of trade goods produced. Assuming you haven't integrated Sabellian culture, you're probably getting the +2 penalty for the territory having an Unintegrated Dominant Culture.

When I have hovered over the grain icon in the summary or the top province part I have not seen a penalty reason

On hovering over the slave icon on the population capacity tab I have seen -30% for "Unintegrated Dominant Culture"
After I have moved around so I have a majority of hellenic roman slaves - the penalty is no longer there. 16 pops -> 3 grain produced

Thank you very much.