Walkthroughs for custom maps.

"Jennifer's Dream Journey" seems a bit more challenging than "Brave People," and both are certainly more difficult than "Wayfarer," but 40+ months is excessive. You can easily complete it in 15 months, and "Brave People" can be finished even faster. Centurion skipped a lot of content, and contrary to the author's intention, he completed the game with Orrin instead of Mephala, which increased the completion time.

If I remember correctly, I finished "Brave People" at the end of the 11th month. A significant portion of the battles take place when we are defending the castle. This is where Mephala's skills are needed to withstand the castle's attacks. You can also play with Orrin, but it will be much more difficult.
The difference in time is that when playing "for yourself," you spend time checking the editor, prospector, testing the map, etc., while on a stream, even though the streamer should do preparation and testing before the stream, they don't dwell on analyzing the prospector and editor, instead focusing on some active actions. Therefore, very often on a stream, it's just a simple accumulation of strength, rather than outsmarting the enemies.