I would purely speculate that they are "an assistant to an assistant." This is an excellent "perk" to the assistant coaches as it frees them up a tad and can get a quick briefing before they dive into their job and can be home a few extra hours at night.
This isnt normal at all. This is reserved for highly intelligent athletes who have their coaches full trust. Only other time I recall this happening at Iowa State is I believe Hoiberg did it with Bryan Peterson. Petersen went from this roll at Iowa State to head coach at Kirkwood. He won 2 junior college national championships at Kirkwood and recently cashed in to become the assistant coach at South Dakota State. My guess is in about 3 years or if he continues being successful he will get his chance to take another step up the ladder.
Also, something no one has mentioned. I believe both Kempt and Lanning are either engaged or married. Obviously their spouse supports this and obviously their spouse has household income as well. If they get $30K a year it isnt ideal but toss in your spouses income and you wont starve as long as both you and your spouse know your time is coming.