Walkthroughs for custom maps.

Hooray! I managed to find a page on a Chinese website with a brief description of the map walkthrough and several screenshots: https://dl.3dmgame.com/patch/110968.html Now I know where to get 10000 gold.
From that Chinese review, I also realized that maps with the abbreviation BT in their title are those where victory in battles is often achieved by repeatedly replaying, hoping for some random favorable factors: repeated attacks due to high morale, fear of our azure troops among enemy forces, etc. I don't remember if anyone mentioned this before (if so, it doesn't hurt to repeat it). You can take this into account when choosing Chinese maps for a Walkthrough. Personally, I don't like this (and "Brave People" is one of such maps, but I will still try to progress further).
Clarification: I just came across a quote explaining the meaning of the abbreviation BT (I misinterpreted it, but luck still plays a big role):

Chinese map ... are often harder than official maps, therefore we call them BT map (BT is short for Chinese words "biantai", means is hardest than normal).