Sounds like those Boeing guys had their hands full. Increasing the height increases the tail aspect ratio giving a steeper lift curve slope and making it more effective. Think Grumman Bearcat. Even with that big prop and short fuselage, it required minimal rudder on takeoff. Tails on the WWI fighters have tiny aspect ratios. They can be deflected to extreme angles without stalling and when they did, it is a gradual break in the lift curve - good things to have in a tail.