i was trying to figure out the simplest way they could have made it better, while staying on their path
Danny's fleet takes heavy losses from wildfire mines, Missandei gets captured and chained to one red keeps towers.
Rhaegal dies at the battle of Kingslands to the ballistas, with Jon seemingly dies to when they crash. which also takes out part of the red keep, killing Missandei. the army of the north breaks and leaves after seeing it happen.
unsullied and dothraki start to get routed as Danny was trying to only attack the armies but was thwarted by the ballistas then sees Grayworm die, goes nuts and burns everything
Ayra tells the hound she is leaving, but tries to kill Cersei and is caught by Queen's Guard. the Hound then has to fight the Mountain to save her
Jon kills Danny when she starts talking of burning the north for fleeing
Jon takes the throne
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in a total redo of season 8, would had all the humans get wrecked and have to cross the narrow sea and try to figure out how to defeat milions of undead as the sea slowly froze.
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also learned a couple of things from some of the history focused youtubers about the kingslanding battle. it was common for armies to come out of their keeps/castle and attack the attackers
attackers would not setup as close as they did as they would got rained on by arrows, catapults and trebuchets, so they would need to be at least 3 football fields away