I've just finished the French and Indian War scenario, playing as the French against British AI. I won in 1760 when the British national morale fell under 75.
The AI did a decent job for the most part, but I noticed it had problems with big stacks of units and their supply. Twice it left a large army in the field for the winter months, which caused serious casualties as the weather became harsh for several turns. One of the stacks was at Fort Oswego. The AI could have built a depot there with its several supply wagons, but it let them become destroyed during the winter turns, along with several regiments of infantry. The second case was with a big army that was besieging Fort Carillon. The stack run out of supply during winter, which made it very easy for me to counterattack and drive back the British. The loss of these two stacks was decisive. The AI was never able to recover from those losses.
I used the easiest attrition setting for the AI. Version was 1.10a, because I only now noticed a new one was recently released (I blame AJE for that!).