Having played BoA in its time, I now strongly enjoy WIA and all the improvements that came with it

I must admit, though, that I am having trouble understanding one of its features.
Among the (great) choice of options the player get to "buy" with his/her victory points, some of them seem to me out of place. This only goes for the FIW scenarii, as I mainly play this war, but applies to both the French and the British.
On one side, you can decide whether to form supply trains, raise militia, recruit Indians, or build batteries at strategic sites. And above all, you can build boats on the lakes, which I beleive is one of the best things that happened to this game.
All those actions look historicaly credible. In term of manpower, one can assume the colonial administration had enough power to get itself a few more militias or Indian warriors. As for the rest, there is nothing wrong either. Supply trains could be simply built from the material at hand and filled up with the supply war stocks of both colonies. There was also sufficient artillerie at hand to divert some pieces to key garrisons. After all, Québec had hundreds of pieces for its defense in 1759, only the shortage of munitions prevented the French from using them efficiently. And I'm not even talking about the aborted attempt on the city by Lévis the next year. Furthermore, the building of boats on the lakes was seen by both parties as one of the keys to carry on the war, and they had enough knowledgeable carpenters and material. Hence the huge fleets, in respect to the era, cruising in the Champlain valley and on Lake Ontario.
Now, on the other side, I'm not sure to see how the option to raise more regulars (replacements for the French, full units for the British) is justified. As I understand it, the player is in the role of the commander in chief of the army in North America, thus leading the war with what means he/her has at hand. Nothing more. If the player is supposed to be left with what the good will of his/her King may want to send him/her, I don't think it should be possible to receive such good reinforcements simply assuming your emissaries in Europe do such a great job at selling your case. In 1759, Bougainville got sent back to Canada with plenty of medals for everyone, but a handfull of crappy muskets and raw recruits. And the British player already get so many more troops as the war drags on, that I don't even see a need for it in that case.
What do you think?
Thanks,
TiFlo