Sorry for the delay in reply. Here in the United States, we have just finished celebrating the Thanksgiving holiday. Despite being a holiday, you're incredibly busy trying to get everything ready, attending social gatherings, etc. I rarely had any free time to play video games, let alone Stronghold. Anyways, onto the post. So yeah, I got my cousin's standard edition last week:
https://u.cubeupload.com/Buzzed_Lightyear/IMG20201203145657.jpeg
After fully uninstalling the Deluxe edition, I made two Alcohol images of the original disks and mounted them in the virtual drive and installed the new standard edition:
After patching the game to version 1.4 (and then later 1.4.1), I was greeted with this upon trying to play the game:
In other words, it works perfectly. So what can we conclude from all of this? That my suspicions were correct: that this issue is specific to the Deluxe Edition of the game, and specifically the 1.3.1 Deluxe Edition Patch. So word to the wise: avoid the Deluxe Edition of Stronghold 2. There's something wrong with that version for whatever reason.