I like the game however the endgame gets really grindy with all the slaves you need to capture. I got everything purchased (all investments, both buildings in Redhaven, the purchased mine and the lumber mill). It was a ton of grind to capture all the slave workers needed to work these places. Now I'm looking at the New World Order quest and seeing the 1800 soldier requirement and I want to tear my hair out. There needs to be a way to bulk purchase slaves if the numbers are going to be this high. Perhaps when you go to the town hall to purchase armies you can actually assign them to your factions rather than it just be an influence purchase.
It's a good design to have the limiting resource shift over time, whether it be money. skill, or NPC affection. However, once you get to the end game it's all about slave bodies and the grind is getting to be too repetitive.