I changed my mind. We shall NOT switch to Serfdorm right now. Serfdorm is good when making heavy improvements like workships and mills, but all we need now is just farming new cities and making basic infrastructure, while we have more than enough improvements for the core cities.
I think we need to stay in Slavery and prepare full scale attack on Gaspar, in 6-8 turns. Let me explain why Gaspar and not DZ or anybody else.
DZ is boxed between scooter, REM and us. He lost his both 7-food-fish locations. This makes me think he will less likely try to make a desperate attack on us to take almost useless city with gems we are providing him anyway.
This also means that if we attack him, scooter and REM will be there and will try to get significant part from DZ or attack us after we take it all or what is worse during our attack.
OTOH, Gaspar has just 1 tight border with REM, so we can expect to catch him unprepared. He has no units inside his land and there is a chance that he has used his GP into Steam Power, so he might have problems with urgent switch to Nationhood. The fact he has moved his machine gun forward is a great sign, we have a nice chance to leave it behind.
Gaspar has strong late game potential, literally he just needs to build his dikes and have fun growing on full sails.
Scooter is far. Pindicator is far. REM can probably take 1-2 cities next to him but it still guarantees that we have a nice front with him in very narrow passage.
So the main idea is to stay on Slavery, whip on the lowest pop since it is the most effective, use 3 stables we have already constructed, produce basic siege and attack. Then we put all cities on growth, adopt serfdorm and continue reinforcing our fronts from drafts. It wont disturb our growth with the number of cities we are going to have.
I will post detailed plan of attack, soon so you can decide if it suits you or not.