Kamikaze pilots were a part of the Japanese Special Attack Units of military aviators who initiated suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, designed to destroy warships more effectively than possible with conventional air attacks. About 3,800 kamikaze pilots died during the war, and more than 7,000 naval personnel were killed by kamikaze attacks. https://en.wikipedia.org/wiki/Kamikaze
There is a claim that the current world record for the longest human cannonball flight is 193 ft 8.8 in (59.05 m), established by David "The Bullet" Smith Jr. on the set of Lo Show dei Record, in Milan, Italy, on March 10, 2011. The distance was measured from the mouth of the cannon to the farthest point reached on the net. David was launched by an 8 m (26' 3") long cannon. It was estimated that he traveled at a speed of 120 km/h (74.6 mph), reaching a maximum altitude of 23 m (75' 6"). https://en.wikipedia.org/wiki/Human_cannonball
Question (part 1)
Assume that combatants are launched from a cannon (or even a ballista) in such a way that the acceleration doesn't kill them (the precise medieval technology is not important for this question). We want them to wreak maximum havoc on the enemy.
Kamikaze pilots could of course steer themselves towards destruction - they were flying planes.
My question is, what sort of simple, medieval-type steering mechanism can the volunteers use whilst in flight to direct themselves towards a given target. What sort of accuracy and course correction can they expect?
Whether they land safely is not a major factor unless they can do more damage that way. Certainly they are not expected to survive in the long run any more than kamikaze pilots were.