Take (A) for example (assuming you have no banked points):
At 11 months, you have 100 points at either BCV or VWL. With borrowing, you have 200 points at either.
At 7 months, you have 200 points anywhere. With borrowing 400.
I'll use UY for my example:
2015 - (100 BCV, 100 VWL) 11 month Reservation for BCV for 150 points - Borrow 50 BCV, Bank 100 BCV
2016 - (50 BCV, 200 VWL) 11 month Reservation for VWL for 225 points - Borrow 25 WVL, Bank 50 BCV
2017 - (150 BCV, 75 VWL) 7 month Reservation for BLT for 160 points - User the 50 Banked BCV points first and decide which other points to use/bank (100BCV+10VWL or 85BCV+75VWL)
It's a bit confusing but as long as you go every year, you can play the bank/borrow game. Make sure the points both have the same UY as that make things much easier to combine at 7 months.
Personally, I think 50 points at any resort isn't enough to use the 11 month advantage as we travel for at least a week at a time (It would be 150 points max, but probably closer to 100). If you were looking for weekend trips, then it might be enough.