but if you waitlist at all 3 at 7 months you will most likely have your pick.
For ex. you book OKW at 11 months, at 7 months you call and you cant complete your ressie at any of the 3, you waitlist for the entire period for each of the 3 resorts, if BWV becomes available first, you switch from OKW to BWV but stay on the Waitlist for the other 2, then maybe VWL becomes avail, and you want to stay there more than you want BWV so you switch and most possibly BCV becomes available and that is where you want to stay the most so you switch to that.
No guarantees, but in 2004, I used the waitlist to switch from BCV to VWL for 10 nights over Christmas. During that time, I had all my waitlists come thru and had my pick. The beauty is, you have a guaranteed ressie and can move forward with all your other plans while you wait for the waitlist.
Many people book at 11 months, but will cancel as their plans change. I for one think the Waitlist is Disneys Best Kept Secret!