I've gotta just laugh at the "why use 4 years?" attitude. One single second of thought would lead you to the why.
I used the last 6 years and the last 4 years of Henson's program. I explained why. 6 reflected what happened after Gill, Bardo, and Liberty were gone. 4, after probation ended..
You cited 5 years. I saw no reason except to get a worse winning percentage and make it look like the program was in worse shape than it was.
The situation Lon inherited was quite a bit better than what Henson and Underwood inherited. Despite Pearl and Slive, Lou still left the program in better shape than he found it.
LK also left it in better shape than he found it, but there is context to that too. He came into a favorable downstate recruiting situation. On the negative side, he was pretty much locked out of Chicago, dimming long range prospects for success.
Was it Pat Kennedy who raked in and wasted all that Chicago talent at DePud? The door was subsequently reopened for UI and Weber was clueless ...