I actually think it might be a pretty good move. If they are really bad (I have no idea about them) then realistically, no one will expect a huge turnaround, so that pressure is not overly intense. But if he can make them show substantial improvement and possibly be competetive, his stock will take a dramatic leap.
By the way, where is FAU located?
FAU is in Boca Raton, and they just started their football program in 2001.
It is a small program and it maybe challenging to get recruits, but if he has success he will get better opportunities at other programs. If they didn't have a down year on defense this season I think he would have had a better shot at a better program.