This is good. We also have to include some members of the last recruiting class who aren't going to make it (L. Stewart) and might not make it (M. Harrison).
Stewart is already off my list but you're right that Harrison would open up another spot.
So, the math for class looks like: 10 seniors, 2 recruits (possibly) not making it to campus, 3 players who left last year (Vestal, Guy, and Okuyemi) = 14-15 scholarships available for this class. Feel free to correct this if I'm missing something!
With 'attrition', I would think 18 would be on the high end. Mavric is probably right with a 16-17 person class.