The following information has been drawn from the below site. It illustrates my point.
http://www.dmna.state.ny.us/historic/articles/bateau.htm
Bateaux, sometimes called "Schenectady Bateaux" or "Schenectady boats," because they were constructed at that village for use on the Mohawk River and ultimately the Great Lakes
Spawn at Albany?
In 1755, Gerret Lansing, of Albany, supplied "oars ...Large Padles...short Padles and Poles with Iron [tips]" for Bateaux to be used in the campaign against Crown Point. (12) In 1758, orders for the expedition against Ticonderoga required "Commanding officers & Regiments to employ their carpenters in making oars, paddles, & scoops," for bailing the Bateaux, since "Each boat will be allow'd from Colonel Bradstreet, only five oars."
The very simplicity of the Bateaux permitted them to be built in large numbers by unskilled or semi-skilled workers and to be readily maintained and repaired or replaced in the field with relative ease
Spawn if, Albany controlled (for supplies), at lakeside region with harbour if a suitably large number of you units have been there for x turns.
First authorized in 1755 by Sir William Shirley, the batteaumen were raised and commanded by Captain (later Lt. Col.) John Bradstreet(36)and were responsible for the construction and operation of the thousands of Bateaux that moved the supplies, equipment, and men of the British and colonial forces up and down the Hudson/Champlain and Mohawk River corridors
Spawn only if Bradstreet batteaumen event has occurred and batteaumen unit has been in lakeside region with harbour, for x turns, to provide the labour.
Bradstreet and his batteaumen played a significant role in the campaign of 1758 from the very beginning. Despite myriad difficulties, 250 bateaux were constructed at Albany before the end of March and Bradstreet confidently promised an additional 1,200 completions by mid-May. By 22 May 1758, he had delivered, as promised, 1,500 Bateaux. This means that Bradstreet was supervising the completion of 120 Bateaux per week at Albany during the two month period April-May 1758, a remarkable achievement.
This gives an impression of the rate of Bateaux production. How the number of real life Bateaux correspond to in game units could be judged from the size of the 1758 forces, in real life and in game. The "myriad difficulties" might require the spawning region to have a depot.
The early months of 1759 saw Bradstreet back in Albany, involved again in preparations for the coming spring campaign and "the tasks he knew so well - bateaux building, procuring bateau-men, carpenters, wagoners & ox team drivers."
Reinforces that Bateaux were a staple, just as much as supply units.
So, from this information alone, my event forumla would be along the lines of...
Check whether the Bradstreet's Bateaumen event has occurred, and if so, then:
Check whether Albany is controlled and if so, then:
Start timer when any harbour on L. Champlain/George/Ontario is controlled
and inhabited by a unit of Bateaumen
and has a depot.
Notify player to keep Bateaumen in region x for x turns.
In the following turns,
Check which of the regions, above, have been inhabited by a unit of Bateaumen for x turns.
Creat units in those regions which satisfy the above.
As for player contolled EP costing reinforcements, i think the same rule might be a bit complicated, what with the player being notified when the conditions are satisfied and then loosing the ability if they then move the Bateaumen away. Simpler i think would be to just check whether the Bradstreet and Albany conditions are satisfied and then spawn them in Albany.
Thoughts?