My castle development strategy often focuses on income (with the exception of small maps and other specific cases). By the end of the third week, I try to build the Capitol and all the monsters, with the 7th-rank monster usually built after the Capitol. Each week, I try to upgrade the castle to the Capitol, but I don't forget to build tactically important monsters and the Citadel and Castle by the seventh day. Let's take the Swamp Castle as an example: In the first week, build Lizards, Wyverns, and possibly Dragonflies, if possible; otherwise, build the Town Hall. In the second week, build the Capitol, or build all the monsters except Hydras, along with the Castle, etc. It depends on the situation.