I have an idea for a change to how mongols outposts are upgraded, have an option to upgrade emplacements.
Say I make an outpost and make it have the Arrowslits Emplacement which cost me 25 gold and 50 stone, now later on in the game I want to upgrade the tower to have Springald Emplacement, there should be an upgrade option that will cost Springald - Arrowslits which would be 25 gold and 75 stone.
- Outpost with Arrowslits upgrade to Springald 25 gold and 75 stone.
- Outpost with Arrowslits upgrade to Cannon 100 gold and 325 stone.
- Outpost with Springald upgrade to Cannon 75 gold and 250 stone.
That way you can upgrade outpost in the early game with the option to make them Springalds and cannons later.