It's hard to pinpoint 1 X factor in an upcoming season like this. Like the post above says, we have at least 8 new players and we'll be counting on most of them to be very productive to have success. Or you could say the X factors might be the health (Fulky) and continued improvement (JJJ, Vescovi, Bailey, etc) of the returning players.
And don't forget, not only will we have a lot of new players. We're replacing 2 assistant coaches. That's a lot of change. I'm a little skeptical that it's all going to come together, but we clearly have a lot of talent.
I'm not sure I'd call a coach with 30+ years of experience an X factor. He has strengths and weaknesses, but at this point he just kind of is what he is.