I learned a lot of what I know about warfare from movies and TV lol, and some reading. I learned about guerilla warfare ("war of detachment") from
Lawrence of Arabia. He would take 100-200 lightly armed units to hit in the middle or back of a force, especially along their supply line or a weakened garrison, then retreat. Like in Warband, this would mess up the enemy because they keep reinforcing the wrong area.
I learned about flanking from Chinese (Warring States period, the time of Sun Tzu who wrote The Art of War, and Three Kingdoms War, where all three armies heavily used flanking, deception and espionage to their advantage) and Mongolian war tactics (their heavy use of multiple cavalry units for front line and flanking). The Chinese generals and strategists were always thinking of tactics to mess with the enemy forces, such as causing a larger army to over-commit a charge against what looks like a weaker force, only to be enveloped and have their retreat cut off. For the curious, this is the same tactic employed in the movies Braveheart (the "Battle of Stirling", which in the movie was actually a combination of the historical battles of Stirling Bridge and Bannockburn), The Patriot (the final battle; another Mel Gibson classic) and The Last Samurai (also the final battle). There are many more sources of course. Suffice it to say that when I watch a war or historical movie, documentary or read a book about war, even in fiction, I spend a lot of time taking mental notes of strategies and tactics employed.

Yup it sure is fun. M&B (Warband especially) is my most favorite game of all time because I purposely make it more fun than most people like to play it. A lot of my friends on Steam that also have the game don't even play it anymore, moving on to other games. But I'm having way too much fun as it is lol. Can't imagine getting tired of this any time soon, especially with Floris mod pack.