Kane will be difficult to replace but you are losing one good Combo guard and adding 1 year experience to his back up Morris, Naz, Thomas, Bluford, and SDW plus adding another top 150 player in Custer. Right there you would say we are better at the guard spot this year. This is not including if Vaughn signs and potentially having Thomas who starts the whole season now coming off the bench.
As far as Ejim goes, he will be replaced with both McKay and Nader. Nader has been rumored to be the best player in practice so far this year and there was talk that when McKay practiced with the team he dominated. McKay adds a level of athleticism that has not been at Iowa State for a long time. There is very real chance that Hogue will be coming off the bench once McKay is eligible. This will go along with Niang, Hogue, and Edozie having another full year of experience.
I will say that with or without Vaughn we will be much improved after next year, in particular once conference play starts and we have McKay in the line up.
While it is fun to speculate how good we will be once each player is a senior, Vaughn is not the only one who may leave to the NBA early.
Niang: Because of his size and game I would put money on him staying 4 years.
Morris: Ranked higher than Trey Burke and playing better as a freshman, I could see him leaving after 3.
Nadar: Has stated he would like to be a one year guy, Good measurable and longest wing span for a player Fred has ever had, if he has a monster year he could leave after 1.
McKay: Most athletic and could lead us in scoring next year, it hurts that he would only have a semester to play but will be against good opponents.
Hypothetically in ISU makes a final four run with Morris, Vaughn, McKay, Nadar, and Niang we could see Vaughn, and possibly Nadar and/or McKay leave next year. With the spot light being on Morris and Niang in there Junior and Senior years respectively.
I would absolutely love that scenario, because that has mean we are now one of the big time programs and other potentially NBA players may start lining up to play Hoiball.