As to ships, why not to implement what 3rd party mission generators like DCG already do: to combine them into 'shippacks' or 'convoys'? The concept is here:
A shippack is an abstract naval unit, a fixed formation with slots for individual ships. Each slot represents a relative position to the formation centre (a vector with distance). Once a ship is assigned to a slot, it becomes a subordinated element of the formation, and from then on, the mission designer can adjust the travelling speed and direction of the whole pack all at once. Direction changes can be twofold:
1) individual elements turn, but the formation's heading remains the same (good for zigzagging or for turning into the wind while starting aircraft);
2) elements turn together with the formation (allows only minor direction changes as the 'outer' ships has to travel more/faster, while 'inner' ships less/slower).
Max speed is of course equal to the slowest element's speed, max turning rate ditto.
Ship formation coding on this basic level is pure mathematics, and it seems to be more easy than to 'teach' individual ships to behave more prudently when in company
