Game of Thrones seems to think they're being badass when something unrelated to the battle plan causes a win. In aSoI&F we get Renly leaving behind all his infantry and supplies to come to grips with one of the top commanders in Westeros, and then goes with a battle plan where the commander is rash & impetuous & chosen for nepotistic reasons over more experienced leaders, and they have to fight soon, because they have no supplies, so they are going to be forced to charge into the rising sun. Meanwhile, we saw Stannis' men practicing their archery earlier in the book, and he has cut down a LOT of trees, in spite of Storm's End being invulnerable to siege engines. The shadow baby that kills Renly probably saved his men from being the victims of a Westeros version of Crecy or Agincourt.

Jaime Lannister decides to lead a column of men on a blind pursuit at night, because, not in spite, of the fact that his scouts have been disappearing.

Roose Bolton force marches his infantry force through the night, only to take up a defensive position and wait for Tywin to order his lines and attack as he chooses, totally sacrificing the element o surprise that is the major benefit to a night march. Then, holding a position up hill with infantry, he has them charge at the enemy, shades of the Saxons at Hastings, without William's feigned retreats for encouragement.

But these guys are portrayed as stupid and rash (and Bolton is a traitor). The writing shows Martin understands some rudimentary facts about warfare. Nobody seems to grasp how stupid the execution of the Battle of the Bastards was, and I doubt they are going to blaming their dispositions allowing the different arms of their forces to be defeated in detail when they are bemoaning how their armies are so depleted that Cersei has the mill-it-tree advantage now.