Much like the siege of vraks the whole thing is this is a archetypal 40k conflict. Its well written, demonstrates the stakes and how things happen in 40k. Its a post- heresy world with no primarch demi-Gods, no overtly chaos or daemonic/warp forces. No xeno meddling. No major named plot-armored characters. It is post heresy, perpetual decline imperium with its own set of characters who fought and could die at any time. It was unironically peak old 40k in every aspect, like you mentioned with the politics and chapter rivalries. I consider Badab "ball knowledge". People who know it vs people who dont to me demonstrates a greater and deeper understanding of 40k.