How do you get past defeat 50 enemies with units affected by the Network of Castles?
I know there may be some deficiencies in their design.
Sometimes the only thing you need is a friend.
You should consider that the bonus that the English have is not only “Defensive”, but also Offensive. Against the AI, try to put a tower or 2 in a clearing, then wait for the enemy army and kill as many of them as possible using the tower’s potential. You can also build a tower near the enemy base, you siege it with your units +20/50% increased attack speed. Count until you kill 50, or 100, just in case.
Try not to rush in that game, or if you rush, leave the enemy alive to reach imperial age and then take advantage of the towers.
In any case, if you want to do it quickly, or you don’t want to lose touch with your rushes, play a game with “maximum resources”, build a wonder before the opponent, wait for him to attack you having several towers and fortresses ready, and an army of archers, knights, ribaudoquin, etc, enhanced by the effect of the towers. High resources guarantee that the enemy will attack you yes or yes, unless he builds a wonder first. If not, you can also put a victory condition only conquer with High resources, and fight to the death, to see who organizes a better siege.